A suffix indicating the ordering of bytes in a multi-byte number, as in big-endian, little-endian, or middle-endian.
.A3L
MacroMedia Authorware Windows Library (filename extension).
.arts
An ending of an address for a cultural site on the Internet. Example: http://www.renaissance.arts.
.cnt
Means: contents. It is a Windows file holding “table of contents” information.
.CRT
Certificate (filename extension).
.FLR
Folder (file name extension).
.gid
Global Index File. It is created by Windows once a help file is used for the first time. It serves as an index reference for the help system thereafter.
.idx
The extension used for an IDX (index file). Index files are not intended to be a readable file, but are used in conjunction with MBX (multi-index) files.
.info
An ending of an address for an Internet site that offers information services. Example: http://www.travelers.info.
.net
A top-level Internet domain name, short for .network.
.NET
Microsoft’s framework for Web services and component software, introduced in 2000 and pronounced “dot-net.”
.newsrc
(news run commands) A file that specifies the configuration for the UNIX rn newsreader.
.pac
1. Atari STAD bitmap image 2.Proxy AutoConfig. 3.SBStudio II package or song
.PDF
The file extension for a Portable Document Format file. Portable Document Format was designed by Adobe Systems, Inc. In order to view a .pdf file the user will need Adobe Acrobat Reader, a freeware product available for download via the Web.
www.fcc.gov/3G/
3GL
Third-generation language. A language like PASCAL or FORTRAN, which is at a higher level than assembly language, and easier to understand.
3W or W3
World Wide Web. A hypermedia-based system for browsing Internet
sites. It is named the Web because it is made of many sites linked together; users can travel from one site to another by clicking on hyperlinks. Text, graphics, sound, and video can all be accessed with browsers like Mosaic, Netscape, or Internet Explorer. The Web can also be accessed with text-only browsers like Lynx.
4-bit color
A monitor with 4-bit color can display 16 colors. Four-bit color is okay for office use, but not good for displaying graphics.
4004
The first microprocessor, released in 1971 by Intel, with a 4-bit register size and bus size, and a clock speed of 1 MHz.
486
Nickname for the 80486. A 32-bit microprocessor from Intel with a built-in coprocessor and a clock speed of 33 MHz.
4GL
Fourth-generation language. A language more advanced than third-generation languages, and closer to regular speech.
4QD
An electronic motor controller used for remote control of robots.
500 number
A telephone number assigned to an individual, rather than a location. A person with a 500 number can get calls, faxes, or data at any location.
56k line
A transmission channel that can transmit data at 56,000 bps.
586
Pentium. The Intel high-performance microprocessor introduced in 1993, also called P5 or 80586. It is about twice as fast as the 486.
6502
An 8-bit microprocessor from MOS Technology, with a clock speed of 1 MHz. It was used in the Apple II.
6502A
An 8-bit microprocessor from MOS Technology, with a clock speed of 2 MHz, used in the Commodore VIC-20.
68000
A microprocessor from Motorola with a 32-bit register size, a 16-bit bus, and a clock speed of 8 MHz, used in the original Macintosh computer.
68020
A microprocessor from Motorola with a32-bit register size and a 32-bit bus, with a clock speed of 16 MHz, used in the Macintosh LC series.
68030
A 32-bit microprocessor from Motorola with a clock speed of 40 MHz, used in the Macintosh IIfx.
68040
A 32-bit microprocessor from Motorola with a clock speed of 40 MHz and a coprocessor.
68060
A 32-bit microprocessor from Motorola with a clock speed of 66 MHz.
680×0
A series of microprocessors developed by Motorola, used in Macintosh computers. See 68000, 68020, 68030, 68040, 68060.
686
The Pentium Pro. Successor to the Pentium microprocessor; also called P6 or 80686. The 686 has internal RISC architecture and a CISC-RISC translator. It is faster than the Pentium for 32-bit software but slower for 16-bit software.
6DOF
Six Degrees of Freedom. A virtual reality term used to describe movement in three-dimensional space.
8-bit color
A monitor with 8-bit color can display 256 colors, which is fine for business and home use, but not good enough for producing high-quality graphics. For multimedia applications, 256 colors is the minimum needed.
8-bit computer
A computer whose central processing unit can process 8 bits of information at a time.
8-bit sound card
A sound card that takes 8-bit samples of a sound wave, measuring the wave on a scale of 256 increments. These older sound cards have been mostly superseded by 16-bit sound cards, which have higher quality sound.
802.x
The set of IEEE standards for defining LAN protocols.
80286
The Intel microprocessor used with the IBM PC AT. Its register size is 16 bits, its bus size is 16 bits, and its clock speed is 8 MHz.
80386
A 32-bit microprocessor from Intel with a clock speed of 33 MHz. The 80386 is used in PCs.
80386SX
A less expensive version of the Intel 80386, with a 16-bit bus.
80486
A 32-bit microprocessor from Intel with a built-in coprocessor and a clock speed of 33 MHz.
80486SX
A less expensive version of the 80486 Intel microprocessor, with no coprocessor.
8051
An 8-bit microprocessor/microcontroller from Intel, with a clock speed of 1-12 MHz.
80586
Pentium. The Intel high-performance microprocessor introduced in 1993, also called P5 or 586. It is about twice as fast as the 486.
80686
The Pentium Pro. Successor to the Pentium microprocessor; also called P6 or 686. The 80686 has internal RISC architecture and a CISC-RISC translator. It is faster than the Pentium for 32-bit software but slower for 16-bit software.
8080
An 8-bit microprocessor from Intel, with a clock speed of 2 MHz. It was the first general-purpose microprocessor.
8086
An Intel microprocessor with a register size of 16 bits and a bus size of 16 bits, with a clock speed of 8 MHz.
8088
The Intel microprocessor used for the original IBM PC. It had a register size of 16 bits, a bus size of 8 bits, and a clock speed of 4.77 MHz.
88000
A series of 32-bit RISC microprocessors from Motorola, beginning with the 88100. These chips have been used in computers made by Data General and Encore.
98lite
A shareware program developed by Shane Brooks which can be used to separate Windows 98 from Internet Explorer for people who want to install only Windows 98.
A
1. Ampere; a charge of one coulomb passing a point in one second. 2. Abbreviation for Angstrom; one 10-billionth of a meter. (The Angstrom abbreviation is actually the Norwegian capital A for the Norwegian letter aa. It has a diacritical mark, a circle, attached to the tip of the A. We could not create it here.)
See also ampere and angstrom entries.
A Programming Language
(APL). A high-level mathematical programming language developed by Kenneth Iverson in the 1960s. It can be run on many different kinds of computers, and is still used for some applications. APL uses its own special characters to represent operations.
A-B box
A box that enables two or more computers to take turns using a peripheral device such as a printer or scanner. The user turns a switch on the box choosing A, B, etc. to change from one computer to another.
Analog-to-digital converter. A device that converts data from analog to digital form. For example, an audio CD is made by converting analog sound signals into digital data.
Auto Answer. Some modems can be set up to accept telephone calls and automatically establish a connection; this ability is called auto answer. When the AA light on the modem goes on, the modem is set to auto answer.
AAT
Average Access Time. The average amount of time it takes for a storage peripheral to transfer data to the CPU.
abend
ABnormal END. From an error message on the IBM 360. Also called a crash or bomb, it is the result of erroneous software logic or hardware failure.
ABI
Application Binary Interface. A specification for the application programming interface (API) and machine language for a hardware platform. The PowerOpen Environment and Windows Sockets are examples of ABIs.
ABIOS
Advanced Basic Input/Output System. A BIOS that is compatible with the latest software and peripherals.
ABIST
Automatic Built-In Self-Test. An automatic self-test performed by an IBM computer to make sure its various components are functioning properly.
abort
To cancel a command or stop a transmission.
Abort, Retry, Ignore, Fail?
A DOS error message that is displayed when the computer has trouble reading a disk or file.
ABR
(Automatic Baud Rate detection). The process in which a receiving device examines the first character of an incoming message to determines its speed, code level, and stop bits. Having this automatic function makes it possible to receive data from different transmitting devices operating at different speeds without having to establish data rates in advance.
abscissa
The x coordinate on an x,y graph (y is the ordinate).
absolute address
A specific location in the memory of a computer or peripheral device, which is not defined by reference to any other address. It is sometimes derived by taking a base address and adding to it a relative address.
absolute cell reference
In a spreadsheet, a reference to one specific cell, rather than a relative reference which would indicate the placement of a cell in reference to the current cell (for example, four rows above in the same column). Since cell references in a spreadsheet are relative references by default, an absolute cell reference must be indicated; this is done by different codes in different programs, but often by adding a dollar sign: $A42, $B$12.
absolute path
A designation of the location of a file which is given in relation to the root directory; it includes the root directory and the descending series of subdirectories leading to the end file.
In a spreadsheet, a reference to one specific cell, rather than a relative reference which would indicate the placement of a cell in reference to the current cell (for example, four rows above in the same column). Since cell references in a spreadsheet are relative references by default, an absolute reference must be indicated; this is done by different codes in different programs, but often by adding a dollar sign: $A42, $B$12.
absolute vector
A vector whose end points are indicated as absolute coordinates.
Abstract Syntax Notation One
(ASN.1). The ISO language for describing abstract syntax.
Alternating Current. Alternating current differs from direct current (DC) in that its direction is reversed 60 times per second (50 times per second in some countries). The electricity in ordinary home or office outlets is AC.
Accelerated Graphics Port
Accelerated Graphics Port. A bus specification from Intel that gives graphics cards faster access to main memory than the PCI bus, thus greatly speeding up graphics display and texture rendering, especially virtual reality and 3D rendering and display. AGP allows efficient use of frame buffer memory, thereby helping 2D graphics performance as well. The coherent memory management design allows scattered data in system memory to be read in rapid bursts. The PCI graphics accelerator bus has a data transfer rate of up to 133 MBps. Because it is directly on the motherboard’schipset and has a direct pipeline connection to the computer’s main memory, AGP is much faster. AGP is available in two speeds: 1X transfers data at a rate of 264 MBps; 2X transfers data at 528 MBps. The AGP 4X, coming in 1999, will double the bandwidth peak again to 1 GBps.
accelerator
A key combination which substitutes for a mouse command, and makes certain operations faster.
A special printed circuit board, usually plugged into one of the computer's expansion slots, that makes the computer work faster. For example, a graphics accelerator card speeds up the time it takes to display images on the computer screen.
acceptable use policy
(AUP). A policy which limits the way a network may be used; for instance, some networks are restricted to noncommercial use.
acceptance test
A formal test conducted by the end user of a system, to determine if the system works according to specifications and should be accepted.
access
To make use of a computer resource.
access code
The password which the user must type in to get access into a computer system.
The mechanisms for permitting or limiting entry to a computer network. Access control manages user access by requiring authentication of the user's identity or membership in a predefined group; it is typically used by system administrators for controlling access to servers, directories or other network resources.
access control protocol
The authentication technology used to verify a user's identity and grant access to a computer or network.
access denied
A message that sometimes appears when requesting a file. When access is denied it may mean the file is already in use, or that access is restricted to specific users.
access line
The telephone line which connects a customer site to the telephone company's central office.
access method
Also termed access mechanism, access method is the manner in which an application reads from or writes to a resource for programming purposes. Access method is the software routine responsible for storing, retrieving, transmitting and receiving data; it is also able to detect errant transfers of data and correct them if possible. Tapes invariably use the sequential access method; disks either use indexed access method, indexed sequential access method or direct access method; communications access methods exchange data from a host computer to remote terminals.
access privileges
The extent to which a user may operate a system resource on a network or a file server. In many cases, permission to access a server, view its contents and modify or create files is limited by the network's system administrator in order to maintain security.
access provider
Service provider; an organization or company that provides access to a network.
The amount of time it takes for a storage peripheral to transfer data to the CPU, measured from the instant the request is made until the instant the data is received.
accessory
A peripheral device that may perform a useful function but is not necessary for the operation of the computer. Examples are printers, scanners, and modems.
ACCU
Association of C and C++ Users. A worldwide association of people who are interested in C, C++, and related programming languages.
ACDI
Asynchronous Communications Device Interface. A software device that permits asynchronous transmission, a way of transmitting data in which one character is sent at a time, and there may be uneven amounts of time between characters. A start bit and a stop bit notify the receiving computer when the transmission begins and ends. In synchronous transmission, strings of multiple characters are transmitted; this method is faster, but more expensive.
ACK
Abbreviation for ACKnowledge. A modem receiving a data packet sends a signal back to the modem that sent it. If the data is complete and correct, it sends an ACK (acknowledgement) signal, which also indicates the next data packet should be sent. If the modem didn't get all the data, it sends back a NAK, or negative acknowledgement signal.
Association for Computing Machinery, 1515 Broadway, New York, NY 10036,
212/869-7440. Since 1947, the Association for Computing Machinery has been advancing information technology throughout the world. ACM offers chapters and activities, special interest groups, conferences and events, journals, magazines and films. ACM has SIGs in programming languages, software engineering, graphics, computer-human interaction, and more. Publications include Computing Reviews and the ACM Guide to Computing Literature, available online, and cover such topics as object technology, participatory design, internetworking, software project management, hypermedia, and wireless computing. ACM also recognizes important contributors in the field of computing.
Acorn Archimedes
A series of personal computers from Acorn Computers, Cambridge, UK; the first personal computers to use RISC architecture.
Acorn Computers Ltd.
A UK computer manufacturer, designer of the Advanced Archimedes, the R140 UNIXworkstation, and the BBC Microcomputer. In 1990 Acorn went into partnership with Apple Computer and VLSI to form Advanced RISC Machines (ARM).
acoustic coupler
A hardware device designed to convert electrical signals to sound, and sound to electrical signals in order to connect a modem to a telephone line via a handset. For current modems that have a direct electrical connection, acoustic couplers are not needed.
ACPI
Advanced Configuration and Power Interface. A power management specification that replaces APM in Windows machines. Developed by Intel, Microsoft, and Toshiba, ACPI gives the operating system the ability to control the amount of power given to each peripheral device, and to turn off devices when not in use.
Acrobat
Document exchange software from Adobe Systems, Inc. Acrobat provides a platform-independent means of creating, viewing, and printing documents. Acrobat can convert a DOS, Windows, UNIX or Macintosh document into a Portable Document Format (PDF) which can be displayed on any computer with an Acrobat reader. The Acrobat reader can be downloaded free from the Internet.
acronym
A word formed from some of the letters (usually the initials) of a phrase, such as RAM (Random-Access Memory). Computer terminology is rich in acronyms.
ACS
Advanced Communications Services.
ACSE
Association Control Service Element. OSI technology used to establish connections between applications.
action statement
An executable command that causes the computer to perform an action.
active cell
The cell in a spreadsheet in which numbers or formulas can be entered. The active cell shows a thick border, and its name is at the top of the screen; also called the current cell.
active component
A device that adds intelligence to a signal or data that passes through it, as opposed to passively permitting its passage without affecting the data in any manner.
The component of Microsoft's Active Platform that acts as an advanced directory service for distributed computing environments. The Active Directory presents applications with a single, simplified set of interfaces so that users can locate and utilize directory resources from a variety of networks while bypassing differences among proprietary services.
active hub
A central device to which other devices connect, and which not only forwards signals, but also amplifies or refreshes the stream of data, which otherwise would deteriorate over a long distance. An active hub is also called a repeater. See also passive hub, intelligent hub.
active matrix display
LCD (liquid crystal display) technology, used for computer screens, in which there is a transistor for each pixel, which prevents losing image quality between scans. Contrast with passive matrix display.
Active Matrix Liquid Crystal Display
(AMLCD). LCD (liquid crystal display) technology, used for computer screens, in which there is a transistor for each pixel, which prevents losing image quality between scans. Contrast with passive matrix display.
Active Server Page
(ASP). A specification for a Web page that is dynamically created by the Web server and contains both HTML and scripting code. With ASP, programs can be run on a Web server in a similar way to CGI scripts, but ASP uses uses the ActiveX scripting engine to support either VBScript or JScript. When a user requests data from an Active Server Page, the ActiveX server engine reads through the file, sends the HTML back to the browser and executes the script. Active Server Pages were first available on the MicrosoftInternet Information Server (IIS) 3.0. They have the .ASP filename extension.
active star
Variant of active hub. An active star is the central connecting device that retransmits and regenerates all signals.
active window
In a graphical user interface, the window in current use, which appears in front of any other open windows on the screen.
active-matrix
A liquid crystal display (LCD) technology used to produce high-quality flat panel color displays, often used in laptop and notebook computers. Active matrix displays use one thin film transistor (TFT) per cell, producing brighter and sharper diplays viewable from wider angles than those produced by passive matrix displays.
ActiveX is a model for writing programs so that other programs and the operating system can call them. ActiveX technology is used with MicrosoftInternet Explorer to make interactive Web pages that look and behave like computer programs, rather than static pages. With ActiveX, users can ask or answer questions, use push buttons, and interact in other ways with the Web page. ActiveX controls are often written using Visual Basic.
ActiveX automation
A set of technologies developed by Microsoft in the 1990s and built on Microsoft's Component Object Model (COM), ActiveX exposes internal functions of a softwareapplication as COM objects so that certain tasks can be “automated” that are normally selected from menus.
ACTOR
An object-oriented programming language for MicrosoftWindows written by Charles Duff of The Whitewater Group Inc., Evanston, IL. It has a Pascal/C-like syntax.
AD
Administrative Domain. Defined in RFC 1136. On the Internet, a group of networks, hosts, and routers operated by the same organization.
ad click
A user’s click on an ad banner. Some ads are paid by the number of user clicks they receive.
ad click rate
The percentage of ad views that result in a user clicking on the ad.
ad view
The downloading of a WWW ad banner which is presumably seen by the user. The number of ad views corresponds to the number of ad impressions in other media. If the same ad appears on more than one page at once, the full number of ad views may not be counted because of browsercaching. Also, there is no reliable way to know whether the ad was fully downloaded and seen by the user.
Ada
A high-level, Pascal-based programming language designed in 1979 for the U.S. Department of Defense. Ada was named after Augusta Ada Byron, Countess of Lovelace. It was designed to enable computers to control automatic equipment, but is also used for other applications.
www.itaa.org), the former Association of Data Processing Service Organizations was formed in the 1960s.
adapter
A part that connects two devices or systems, physically or electrically, and enables them to work together. It can be a plug that allows two wires to be connected, for example, or a printed circuit board that modifies the computer so it can work with certain hardware or software.
Adaptiv Workforce
An application from Adaptiv Software which helps employers manage information about employees, shifts, and pay schedules, and build labor forecasts.
adaptive bridge
A networkbridge programmed to remember destination addresses so that subsequent data will be routed more efficiently
adaptive compression
A technique where the compression algorithm used in the compression of data is chosen based on the characteristics of the data. Adaptive compression chooses the algorithm that offers optimal compression and the fastest transmission speed.
adaptive differential pulse code modulat
(ADPCM). A technique of translating analog sound into digital format that takes less computer memory than the regular pulse code modulation used by audio CDs. It is used on the Sony minidisk, and for CD-ROMs which have images and other data as well as sound. ADPCM takes rapid samples of sound and translates them into binary code, but instead of coding an absolute measurement at every sample point, it codes the difference between samples. ADPCM is used for long-distance telephone lines and outer-space communications because it eliminates errors in transmission.
Adaptive equalization
Adaptive equalization enables two modems to adjust the speed and modulation method of data transfer automatically based on the quality of the phone connection, increasing speed in optimal conditions and slowing down in high-risk situations.
Adaptive routing
The feature in a networksoftware that allows the network to choose the best available path for data transfer.
adaptive suspension vehicle
(ASV). An advanced walking robot that is 16 feet long, 10 feet high, and weighs 6,000 pounds. The ASV has six legs and can sprint at eight miles per hour and step over a four-foot wall.
ADB
The Apple Desktop Bus is a serial communications pathway built in to all pre-G4 Apple Macintosh computers (except the iMac and the iBook) that permits communication between low-speed input devices like the keyboard, mouse, trackball and graphics tablet and the computer. The ADB can connect up to 16 input devices simultaneously.
ADC
Analog-to-Digital-Converter. A device that converts data from analog to digital form. For example, an audio CD is made by converting analog sound signals into digital data.
Administrative Directory Management Domain. A directory management domain that uses the X.500protocol, run by a Postal, Telegraph, and Telephone authority.
address
1. The identifying location of a device or an area of storage; for example, a memory register, disk sector, or network node. 2. To identify with an address.
address bus
Connections between the central processing unit (CPU) and memory which transmit the address from which the CPU will read, or to which the CPU will write. (The data is transmitted via the data bus.) The amount of memory the CPU can address is determined by the number of bits in the address bus.
address mask
A pattern of characters, 32 bits long, used to select some of the bits from an subnet. It selects the network part of the address and some of the local information.
address resolution
Translation of an Internet address into its physical address (MAC or Ethernet address), which is the actual number of the machine. This address is usually found using Address Resolution Protocol.
Address Resolution Protocol
(ARP). The Internetprotocol which maps IP (Internet Protocol) addresses to physical addresses on local area networks so that packets can be transmitted. It is defined in RFC 826. An ARP request is broadcast onto the network for a particular IP address, and the node with that address replies with its physical address.
address space
1. The address space of a computer or processor is the range of addresses it can access, including physical memory and virtual memory. 2. The address space of a program or process is the range of memory it uses while running, including physical memory, virtual memory, or both.
Administration Management Domain or Administrative Management Domain.
A public email message service that uses the X.400 protocol. ATTmail and MCImail are examples. The X.400 backbone is made up of ADMDs all over the world.
admin
System administrator. The person in charge of a multiuser computer system, also called sys admin. The system administrator designs the system and manages its use.
Administration Management Domain
(ADMD). A public e-mail message service that uses the X.400 protocol. ATTmail and MCImail are examples. The X.400 backbone is made up of ADMDs all over the world.
Administrative Directory Management Doma
(ADDMD). A directory management domain that uses the X.500 protocol, run by a PTT (Postal, Telegraph, and Telephone) authority.
(ADMD). A public e-mail message service that uses the X.400 protocol. ATTmail and MCImail are examples. The X.400 backbone is made up of ADMDs all over the world.
administrator
An administrator performs the service of maintaining a network resource, including registering users and user passwords.
Adobe Acrobat
Document exchange software from Adobe Systems, Inc. Acrobat provides a platform-independent means of creating, viewing, and printing documents. Acrobat can convert a DOS, Windows, UNIX or Macintosh document into a Portable Document Format (PDF) which can be displayed on any computer with an Acrobat reader. The Acrobat reader can be downloaded free from the Internet.
Adobe Illustrator
A draw program for Macintosh and Windows. It is especially useful for technical drawing.
www.adobe.com.
Adobe Type Align
A program from Adobe Systems that can be used to align type with selected shapes for special effects; for example, making text curve around a semicircle.
Adobe Type Manager
(ATM). A font utility for Macintosh and Windows that enables a computer to print PostScript fonts and show PostScript screen fonts.
ADP
Automatic Data Processing. The processing of information by means of a computer.
ADPCM
Adaptive Differential Pulse Code Modulation. A technique of translating analog sound into digital format that takes less computer memory than the regular pulse code modulation used by audio CDs. It is used on the Sony minidisk, and for CD-ROMs which have images and other data as well as sound. ADPCM takes rapid samples of sound and translates them into binary code, but instead of coding an absolute measurement at every sample point, it codes the difference between samples. ADPCM is used for long-distance telephone lines and outer-space communications because it eliminates errors in transmission. Also called Adaptive Digital Pulse Code Modulation.
ADSL
Asymmetric Digital Subscriber Line, or Asymmetric Digital Subscriber Loop. A digital subscriber line (DSL) technology in which the transmission of data from server to client is much faster than the transmission from client to server. Whereas with HDSL (High-Speed Digital Subscriber Line), transmission is 784 kilobits per second in both directions, with ADSL, the rate from client to server is 640 kilobits per second and from server to client can be up to 6 megabits per second. This kind of connection is useful with applications such as interactive TV and Video on Demand, because the data the server sends is much more than the data sent by the client. ADSL uses bandwidth that is not used by voice; therefore voice and data can be transmitted at the same time.
Advanced Configuration and Power Interfa
(ACPI). A power management specification that replaces APM in Windows machines. Developed by Intel, Microsoft, and Toshiba, ACPI gives the operating system the ability to control the amount of power given to each peripheral device, and to turn off devices when not in use.
(AMPS). A standard for analog cellular phone service used in the United States and other countries.
Advanced Peer-to-Peer Networking
(APPN). IBM data communications support that routes data between APPC systems to enable users anywhere on the network to have direct communication with each other.
Advanced Power Management
(APM) A feature from Intel and Microsoft for battery-powered computers, which powers-down or the display when the computer has been inactive for a certain length of time in order to conserve power. Monitors with this energy-saving capability are called “green monitors”.
Advanced Program-to-Program Communicatio
(APPC). An IBM communications protocol that allows shared processing of programs on a network.
Advanced Research Projects Agency
(ARPA) An agency of the U.S. Department of Defense that developed technology for the military. ARPANET, which was one of its projects, grew into the Internet.
Advanced Research Projects Agency Networ
(ARPANET). A wide area network developed in the 1960s by the Advanced Research Projects Agency of the U.S. Department of Defense, that linked government sites, academic research sites, and industrial sites around the world. Later, the military communications part split off and was named MILNET. ARPANET was the testing ground and original backbone of the Internet.
Advanced RISC Machine
(ARM). One of a number of 32-bitRISCmicroprocessors for computing, games, multimedia, and many other uses. They are energy-efficient and economical.
1. (AWE). A series of sound cards from Creative Labs that includes the Sound Blaster AWE 32, the Sound Blaster AWE64, and the AWE64 Gold. The AWE64 can play in 64 voices at the same time using Wave-Table synthesis, and has Plug and Play installation. 2. The engine used with the AWE sound cards.
Advent
(Adventure). One of the first text-based adventure games, which was a model for many games to follow. The name Adventure was shortened to Advent because the computer only allowed 6-letter file names.
Adventure
(Same as Advent). One of the first text-based adventure games, which was a model for many games to follow. The name Adventure was shortened to Advent because the computer only allowed 6-letter file names.
AFC
Automatic Frequency Control.
AFE
Apple File Exchange. In a Macintoshoperating system, the AFE utility program allows the Mac to read and record data files from a floppy disk formatted for use on a PC.
A screen saver program for from Berkeley Systems, Inc., that allows users to create custom animations. There are versions for Macintosh and PC. Two of the best-known After Dark screen savers are the flying toasters and flying toilet seats.
AFUU
Association Francaise des Utilisateurs d'Unix. The French Association of Unix Users.
AFY2KDB
Air Force Year 2000 Database. A centralized database on Year 2000 matters maintained at Scott Air Force Base by INET.
agent
A software program that performs a service, such as alerting the user of something that needs to be done on a certain day; or monitoring incoming data and giving an alert when a message has arrived; or searching for information on electronic networks. An intelligent agent is enabled make decisions about information it finds.
aggregation
A computer security violation which is accomplished by collecting nonprivileged data and using it to extrapolate privileged data.
AGP
Accelerated Graphics Port. A bus specification from Intel that gives graphics cards faster access to PCI bus, thus greatly speeding up graphics display and texture rendering, especially virtual reality and 3D rendering and display. AGP allows efficient use of frame buffer memory, thereby helping 2D graphics performance as well. The coherent memory management design allows scattered data in system memory to be read in rapid bursts. The PCI graphics accelerator bus has a data transfer rate of up to 133 MBps. Because it is directly on the motherboard'schipset and has a direct pipeline connection to the computer's main memory, AGP is much faster. AGP is available in two speeds: 1X transfers data at a rate of 264 MBps; 2X transfers data at 528 MBps. The AGP 4X, coming in 1999, will double the bandwidth peak again to 1 GBps.
AI
Artificial Intelligence. Intelligence that mimics human intelligence, when exhibited by devices and applications such as robots or computers with voice recognition and language processing ability. This human-like intelligence implies the ability to learn or adapt through experience.
(Audio Interchange File Format) A format developed by Apple Computer for storing high-quality sampled audio and musical instrument information. It can be played on PC and Mac, and is used by some professional audio software packages.
AIM
AOL Instant Messenger. The instant messaging program of America Online.
Aimnet
An Internet access provider in Cupertino, CA, U.S.A.
Air Force Year 2000 Database
(AFY2KDB). A centralized database on Year 2000 matters maintained at Scott Air Force Base by INET.
AIX
Advanced Interactive eXecutive. IBM's version of UNIX.
Muhammad ibn Musa Al-Khawarizmi (ca. 780 – ca. 850), a Persian mathematician who introduced Arabic numerals and decimal calculation to the west. The word "algorithm" is derived from his name.
Aladdin Systems
The developers of Stuffit, the file compression utility for Macintosh.
alarm filtering
The ability of a network management system to precisely identify the device that has failed.
A signal from the computer that something requires the user's attention. It may be an error message or warning, and is often indicated with an alert box, a sound, or flashing words or images.
alert box
A box that pops up on the computer screen, often with a beep or other sound, to give a warning or error message. The user must hit the return key or click to acknowledge the message before continuing.
Alexa
A free Webbrowser enhancement linked to a database of over 400 million Web page archives. When Web surfers attempt to load a page that no longer exists they can simply choose the Alexa button on their toolbar and Alexa will attempt to retrieve the page from their archives.
algebra
A system of mathematics or logic in which abstract entities are represented in symbolic form and used in operations similar to arithmetic.
algebraic expression
An expression which uses symbols to represent numbers or abstract concepts for use in operations similar to arithmetic.
ALGOL
ALGOrithmic Language. A high-level compiler language for scientific computations. Two versions were developed: ALGOL 60, developed by an international committee in 1960; and ALGOL-68, a more complicated version released in 1968. ALGOL was the inspiration for Pascal.
algorithm
A detailed, ordered set of instructions for solving a problem. Named after Al-Khawarizmi, an Iranian mathematician. This term is used in computer programming to refer to instructions given to the computer.
ALGOrithmic Language
(ALGOL). A high-level compiler language for scientific computations. Two versions were developed: ALGOL 60, developed by an international committee in 1960; and ALGOL-68, a more complicated version released in 1968. ALGOL was the inspiration for Pascal.
alias
1. An abbreviation for an e-mail address that, when keyed in, sends the message to the complete address. 2. An alternate label for identifying an object, such as a file or data field. 3. A false signal created in the digitization of an analog audio sample.
aliasing
In computer graphics, the stairstepped appearance of diagonal or curved lines. Aliasing also refers to false frequencies in digitized sound.
alignment
Where text or other graphic elements are placed on the page in relation to other elements or the margins. For example, right-aligned text lines up with the right margin.
all-stations address
An address (such as 11111111) which will send a message to all stations on a network.
ALM
Assembly Language for Multics (Multiplexed Information and Computing Service). An early (1969) timesharing operating system, developed by MIT, GE, and Bell Laboratories, and introducing many new operating system features.
ALOHA
A transmission system developed at the University of Hawaii using time division multiple access (TDMA) technology. It has been used for satellite and terrestrial radio links. A packet is broadcast when ready, and if a collision occurs it is retransmitted. A variation called Slotted ALOHA sends packets at specific time slots to reduce the number of collisions.
Aloha Net
One of the first computer networks in the U.S.A., at the University of Hawaii, Manoa. It was initiated in the early 1970s, and used key punch cards and sent commercial telephone lines.
Alpha
A family of 64-bit RISC-based microprocessors from Digital, used with the Alpha AXP and other computer systems.
Alpha Processor
This is a RISC processor that was created by the Digital Equipment Corporation for their line of workstations and servers. These processors are the only microprocessors that run Windows NT outside of the traditional x86 microprocessors.
alpha testing
Testing new software in the factory by either the manufacturer's staff or outsiders. The next stage is beta testing, which is done by actual users in the kind of environment in which the software will be used.
alphanumeric
Using alphabetic letters, numbers, and special characters.
alphanumeric display
A display, usually a LCD, that shows alphabet characters and numbers.
alt
Top-level newsgroup category for a newsgroup with alternative discussions. Some of the topics are practical, some humorous, some bizarre. This category of newsgroup was created to avoid the bureaucratic process of forming a certified newsgroup.
alt key
The Alt key on a computer keyboard gives alternate meanings to other keys, thus expanding the keyboard's capability. The Alt key is held down like a Shift key, and another key is pressed.
Altair
An early microcomputer for hobbyists, sometimes called the world's first microcomputer.
AltaVista
A World Wide Web site hosted by Digital with a very fast Web and Usenet search engine, and one of the largest Web indexes. AltaVista can be found on the web at www.altavista.com.
alternate routing
Using another transmission channel when the regular channel is busy.
alternating current
(AC). An electric current that reverses its direction at regular intervals. See direct current.
ALU
1. Arithmetic & Logic Unit. The part of a computer's central processing unit which performs arithmetic operations on integers, and Boolean operations. Floating-point operations are handled by a separate floating-point unit. 2. (Association of Lisp Users). An international user group for the Lisp programming language.
AM
Amplitude Modulation. Blending a signal into a carrier wave by varying the amplitude of the carrier; also a broadcasting system that uses this kind of modulation.
AMD
1. Active Matrix Display. LCD (liquid crystal display) technology, used for computer screens, in which there is a transistor for each pixel, which prevents losing image quality between scans. Contrast with passive matrix display. 2. Advanced Micro Devices, Inc., A U.S. manufacturer of integrated circuits, microprocessors, memory, and other computer products.
Amdahl Corporation
A Sunnyvale, California computer company founded by Gene Amdahl. Amdahl Corporation products include IBM-compatible mainframes, UNIX servers, applications development software, and other products and services.
Amdahl, Gene
Founder of Amdahl Corporation, later involved with Trilogy, and Andor Corporation.
>www.aol.com< offers e-mail, interactive newspapers and magazines, conferencing, software files, computing support, and online classes, in addition to full Internet and World Wide Web access.
American National Standards Institute
(ANSI). An organization that develops standards for many things, only some having to do with computers, such as properties of diskettes, programming languages, etc. ANSI is the U.S. member of the International Electrotechnical Commission (IEC). ANSI standards are voluntary. ASCII is an ANSI character set.
American Standard Code for Information I
(ASCII). A code in which each alphanumeric character is represented as a number from 0 to 127, translated into a 7-bit binary code for the computer. ASCII is used by most microcomputers and printers, and because of this, text-only files can be transferred easily between different kinds of computers. ASCII code also includes characters to indicate backspace, carriage return, etc., but does not include accents and special letters not used in English. Extended ASCII has additional characters (128-255).
American Telephone and Telegraph, Inc.
(AT&T). One of the largest corporations and telecommunications carriers in the United States. AT&T has been incorporated since 1885, and has provided telephone service throughout the United States and in other countries. AT&T was parent company of the Bell System of telephone companies, a monopoly which was dissolved in 1984 by a Federal court order. AT&T continues to be a competitive long distance telephone carrier. AT&T has been credited with breakthroughs in technology, including the UNIXoperating system and the C and C++ programming languages. At&T can be found online at www.att.com.
Ami Pro
A word processing program developed by Samna Corporation for DOS and Windows. It was later bought by Lotus, and has been replaced by Word Pro.
Amiga
A group of home computers developed by Commodore Business Machines. Amigas have a graphical user interface and are used for games, video processing, multimedia, office applications, and desktop publishing. The German company Escom AG bought Commodore in April 1995.
Astronomical Markup Language. A standardized format for exchange of metadata related to astronomy. This language will enhance the ability of astronomers to retrieve scientific data, and make it possible for humans and intelligent agents to use the same information. Humans can view AML documents by means of a Java AML browser; intelligent agents can use an Extensible Markup Language (XML)parser.
AMLCD
Active Matrix Liquid Crystal Display. LCD (liquid crystal display) technology, used for computer screens, in which there is a transistor for each pixel, which prevents losing image quality between scans. Contrast with passive matrix display.
AMMA
Advanced Memory Management Architecture. Strategies for providing sufficient memory to all the processes in a computer system, performed by the memory management unit.
Ampere
The basic unit of electric current in a circuit. A charge of one coulomb passing a point in one second.
ampersand
ASCII character 38: & “and”. Sometimes called pretzel.
amplitude
The maximum value of a quantity that varies periodically, such as an alternating current or wave.
amplitude modulation
(AM). Blending a signal into a carrier wave by varying the amplitude of the carrier; also a broadcasting system that uses this kind of modulation.
AMPS
1. Analog Mobile Phone System. Non-digital cellular mobile phones. 2. Advanced Mobile Phone Service (Motorola).
analog
Representing data in continuously variable physical quantities, in contrast to the digital representation of data in discrete units (the binary digits 1 and 0). Analog systems handle information which is represented by continuous change and flow, such as voltage or current. Analog devices have dials and sliding mechanisms. Digital information, in contrast, is either on or off. An analog is a representation of a pattern by a similar pattern; for example, an analog clock represents the sun circling around the earth. An analog device converts a pattern such as light, temperature, or sound into an analogous pattern. An example is a video recorder, which converts light and sound patterns into electrical signals with the same patterns. An analog signal such as a sound wave is converted to digital by sampling at regular intervals; the more frequent the samples and the more data recorded, the more closely the digital representation resembles the analog signal. Converting analog signals into digital makes it possible to preserve the data indefinitely and make many copies without deterioration of quality.
analog channel
A voice or video communication channel which carries a signal with varying frequencies. Compare digital channel.
analog computer
A computer that uses analog methods to process data. An analog computer operates with numbers represented by directly measurable quantities (such as temperature changes or voltages) which vary continuously, whereas a digital computer works with signals which are either on or off (binary 0 or 1). All ordinary computers are digital; analog computers are employed for special uses, such as robotics, where an experimental design can be tested in real time.
analog-to-digital converter
(ADC). A device that converts data from analog to digital form. For example, an audio CD is made by converting analog sound signals into digital data.
Analytical Engine
A computing machine conceived in 1830 by Charles Babbage. He received inspiration from his work on the “Difference Engine.” The Analytical Engine was never completed, though Babbage worked on it until his death in 1871. It was intended to compute decisions based on prior computations and loops founded on Jacquard's punched cards. Babbage is often credited as being “the father of computers” for his work on the Analytical Engine.
Anarchie
A shareware application from Stairways Software which provides fast FTP (file transfer protocol) and Web connections.
AND
One of three logical operations of Boolean logic. The AND operation is true when the combining of two bits (0,1) or two Boolean values (false or true) is such that both inputs are true. See also Boolean algebra, Boolean operators, OR and NOT.
AND gate
A Boolean logic gate used in computer arithmetic. The AND gate has an output of 1 only if all of its inputs are 1. See also Boolean algebra, Boolean operations, and AND.
ANDF
Architecture Neutral Distributed Format. An intermediate language created by The Open Group to use in developing UNIXsoftware.
angle brackets
The Keyboard symbols <>. Angle brackets are commonly used to enclose HTML tags and other codes.
Automatic Number Identification. A service that identifies the telephone number of each incoming telephone call.
animated graphic
An animated image produced by means of a series of computer graphic images; for example, a moving cartoon or diagram. Animated graphics add interest to a presentation, and use much less disk space than video images.
anisochronous transmission
A way of transmitting data in which there is always a whole number of unit intervals between any two significant instants in the same block or character, but not between significant instants in different blocks or characters. See isochronous transmission.
anisotropic
Not isotropic; having properties that vary depending on the direction of measurement. An example would be a transmission speed that is faster in one direction than another.
ANN
Artificial Neural Network. A network of many simple processors that imitates a biological neural network. Neural networks have some ability to “learn” from experience, and are used in applications such as speech recognition, robotics, medical diagnosis, signal processing, and weather forecasting.
A way of getting files from FTP sites on the Internet that have files available for public download. To transfer files using anonymous FTP, you must log in as “guest” or “anonymous” and enter your e-mail address as the password. Many of these sites are provided by universities and government agencies. The publicly available files are usually in a directory called “pub”, which is isolated from the files used by other users on the system and will not accept uploads from anonymous users.
The ANSI (American National Standards Institute) extended character set used with MicrosoftWindows. There are 256 characters. The first 128 characters are the standard ASCII character set; the second 128 are special characters such as math symbols and foreign language accents. The second 128 characters differ from the extended ASCII characters used on the PC.
The study and development of of human-like robots.
anti-aliasing
Smoothing the jaggies in a bitmapped image. When diagonal or curved lines are put in bitmapped form, these shapes must be made with square pixels; any lines that are not vertical or horizontal have a stair-stepped appearance. Anti-aliasing changes the pixels along the edges of the line into varying shades of gray or in-between color, in order to make the edge appear smoother. In a black-on-white image, for example, the shade of gray used is determined by how much of the in-between pixel overlaps the black area and how much overlaps the white area.
antiglare screen
A screen that is attached to the front of a computer monitor to reduce glare, thus easing strain on the user's eyes. Contrast with antiglare treatment.
antiglare treatment
A treatment of the glass of a monitor which reduces reflected glare by absorbing or diffusing light. Some methods which have been used are a silica-based coating, optical lenses, and mechanical etching. Many users prefer an antiglare screen attached to the front of the computer instead of antiglare treatment.
antivirus program
A program that detects and removes computer viruses.
antivirus software
A program that will detect and remove computer viruses.
Anyware Software, Inc.
A Los Angeles, California company that develops computer security and antivirus products for DOS and Windows.
AOCE
Apple Open Collaboration Environment. Macintosh System 7 extensions that make it possible to share e-mail, directory, and other services in a multiplatform environment.
>www.aol.com<. One of the largest providers of online services. AOL offers e-mail, interactive newspapers and magazines, conferencing, software files, computing support, and online classes, in addition to full Internet and World-Wide Web access. AOL announced a merger with Time Warner Inc. in 2000.
The Apache Project is a collaborative software development effort aimed at creating a robust, commercial-grade, featureful, and freely-available source code implementation of an HTTP (Web) server. The project is jointly managed by a group of volunteers located around the world, using the Internet and the Web to communicate, plan, and develop the server and its related documentation. These volunteers are known as the Apache Group. In addition, hundreds of users have contributed ideas, code, and documentation to the project.
APCUG
Association of Personal Computer User Groups. A nonprofit organization dedicated to encouraging communication among different user groups, and between user groups and vendors.
API
Application Program Interface. An interface between the operating system and application programs, which includes the way the application programs communicate with the operating system, and the services the operating system makes available to the programs. For example, an API may make it possible for programs that run under it to open windows and display message boxes.
APL
A Programming Language. A programming language for notating mathematical algorithms, developed by Ken Iverson at Harvard University.
APM
Advanced Power Management. A feature from Intel and Microsoft for battery-powered computers, which powers-down or the display when the computer has been inactive for a certain length of time in order to conserve power. Monitors with this energy-saving capability are called “green monitors”.
Apollo Computer, Inc.
A maker of high-performance workstations, and a pioneer in workstationnetworking. It became a division of HP in 1989.
Advanced Program to Program Communications. An IBM communications protocol that allows shared processing of programs on a network.
Apple Computer, Inc.
One of the largest personal computer manufacturers, located in Cupertino, California. The company was founded by Steve Jobs and Steve Wozniak, in a garage. The Apple II, released in 1977, became very popular for educational use. VisiCalc, the first computer spreadsheet, was designed for the Apple II. Another computer in the Apple line was the Lisa, introduced in 1983. In 1984, Apple released the first Macintosh computers. The graphical user interface and mouse of the Macintosh revolutionized personal computing, and Macintosh quickly became popular for desktop publishing. In the 1990s, Apple Computer, IBM, and Motorola began working together to develop compatible products, and in 1994, the PowerMac came out. Based on the PowerPC microprocessor, it can run both Macintosh, DOS, and Windows applications. Other Apple products are the PowerBook laptops and the Newtonpersonal digital assistant. Apple can be found on the Web at www.apple.com.
Apple Desktop Bus
(ADB). Port on the Macintosh for a keyboard, a mouse, and other peripherals.
Apple II
An 8-bit microcomputer introduced by Apple Computer in 1977 that became very popular for school and home use. The first personal computer spreadsheet, VisiCalc, was developed for the Apple II. Invented by Steve Wozniak, the Apple II originally had a 6502 processor and 4K RAM.
Apple II+
An improved Apple II introduced in 1979, with 48K of RAM and a screen resolution of 280x192x6.
Apple IIc
A portable Apple II released in 1984, the same year the Macintosh made its first appearance. See also Apple.
Apple IIe
An enhanced version of Apple II released in 1983, with 128K RAM.
Apple IIGS
An Apple II with enhanced graphics and sound, released in 1986. It had a 16-bit 65C816 CPU and 320x200x256 screen resolution.
Apple III
An Apple microcomputer introduced in 1980 for business use. It never became as popular as the Apple II.
Apple Mac
Apple Macintosh. A family of 32-bit personal computers introduced by Apple in 1984; the first widely used computers with a graphical user interface, a mouse, and windows. Rather than typing in commands, users open software and copy or delete files by clicking on icons on the screen that look like file folders, a trash can, and other things one would find in a real office. Macs quickly became popular because of their user-friendly interface. In 1994, PowerMacs, which use a PowerPC CPU, became available. The Macintosh Operating System is now called MacOS. Apple is located at http://www.apple.com.
Apple Macintosh
A family of 32-bit personal computers introduced by Apple in 1984; the first widely used computers with a graphical user interface, a mouse, and windows. Rather than typing in commands, users open software and copy or delete files by clicking on icons on the screen that look like file folders, a trash can, and other things one would find in a real office. Macs quickly became popular because of their user-friendly interface. In 1994, PowerMacs, which use a PowerPC CPU, became available. The Macintosh Operating System is now called MacOS.
(AOCE). Macintosh System 7 extensions that make it possible to share e-mail, directory, and other services in a multiplatform environment.
AppleScript
An object-oriented shell language and command-line interface for Macintosh, beginning with System 7 Pro.
AppleShare
File server software developed by Apple Computer, Inc. for Mac OS users that allows filesharing between Macintosh computers on the same network.
AppleSoft BASIC
A version of BASIC for Apple computers, originally installed with all Apple II models.
applet
A little application. An applet can be a utility or other simple program. On the World Wide Web, there are many applets written in Java language which are attached to HTML documents.
AppleTalk
A local area networkprotocol developed by Apple Computer for communication between Apple Computer products and other computers. There are implementations for LocalTalk, EtherTalk, and Token Ring networks. A PC can connect to an AppleTalk network using an adapter card; UNIX and 6025″>VAX computers can also be set up to use AppleTalk.
A program that helps the user accomplish a specific task; for example, a word processing program, a spreadsheet program, or an FTP client. Application programs should be distinguished from system programs, which control the computer and run those application programs, and utilities, which are small assistance programs.
application binary interface
(ABI). A specification for the application programming interface (API) and machine language for a hardware platform. The PowerOpen Environment and Windows sockets are examples of ABIs.
Application Configuration Access Protoco
(ACAP) Formerly known as Internet Message Support Protocol (IMSP), ACAP is an e-mail protocol that allows access to related email servers such as mailboxes, addresses and bulletin boards. ACAP was initiated by the Internet Engineering Task Force (IETF), a standard-setting organization for the Internet. It was designed to complement Internet Message Access Protocol, a protocol for retrieving messages and searching for keywords within messages while they are still on the server.
application layer
Layer 7 of the Open Systems Interconnection (OSI) networking model, which defines standards for interaction at the user or application program level; for example, formatting electronic mail messages, reading and writing files, and file transfer. It is the highest layer of the protocol stack.
application program
A program that helps the user accomplish a specific task; for example, a word processing program, a spreadsheet program, or an FTP client. Application programs should be distinguished from system programs, which control the computer and run the application programs, and utilities, which are small assistance programs.
application program interface
Variant of Application Programming Interface (API). An interface between the operating system and application programs, which includes the way the application programs communicate with the operating system, and the services the operating system makes available to the programs. For example, an API may make it possible for programs that run under it to open windows and display message boxes.
application programming interface
(API). An interface between the operating system and application programs, which includes the way the application programs communicate with the operating system, and the services the operating system makes available to the programs. For example, an API may make it possible for programs that run under it to open windows and display message boxes.
application server
Software operating among browser-based computers, back-enddatabases, and business applications. Server applications assist in translating HTML commands so that databases can interpret them.
application sharing
A conferencing capability that allows two or more users work on the same application, at the same time.
application software
The programs that help the user accomplish tasks; for example, word processing programs, spreadsheet programs, or FTP clients. Application software is distinguished from the system software, which controls the computer and runs the application programs; and utilities, which are small assistance programs.
Microsoft Office and Windows Me are examples of application suites.
Application System/400
(AS/400). A family of IBM minicomputers designed primarily for business applications.
application viewing
A conferencing capability that lets two or more users view the same application at the same time, where only the user with the machine containing the application can edit the document. Contrast with application sharing.
application-specific integrated circuit.
(ASIC). A customized microchip which is designed for a specific application.
APPN
Advanced Peer to Peer Networking. IBM data communications support that routes data between Advanced Peer-to-Peer Communication (APPC) systems to enable users anywhere on the network to have direct communication with each other.
Aptiva
A family of home PCs from IBM, with home office software, Internet software, and multimedia features such as full-motion video, 3-D graphics, and surround-sound.
ARAG
AntiReflection AntiGlare. There are add-on screens for monitors that eliminate screen glare and protect the user’s eyes.
ARCA
Advanced RISC Computing Architecture. RISC–Reduced Instruction Set Computing–is a microprocessor design which is intended to make operations run faster by processing a few simple instructions rather than many complex ones. CISC–complex instruction set computing–processors do more of the processing of complex operations within the CPU than RISC processors, which require certain operations to be performed by the software before the data gets to the CPU. The operating system must be set up for RISC, and the applications used must be compiled specifically for RISC architecture, otherwise the RISC processor must emulate a CISC processor, and the benefits of RISC are lost. Examples of computers with RISC architecture are the IBM RISC Sytem/6000, the PowerPC, and the PowerMac.
Archie
(ARCHIvE). An Internet utility used for locating files that are accessible by anonymous FTP.
Archimedes
A series of personal computers from Acorn Computers, Cambridge, UK; the first personal computers to use RISC architecture.
(ANDF). An intermediate language created by The Open Group to use in developing UNIX software.
archival backup
1. A routine that makes it possible to back up only the files that have changed since the last backup, instead of backing up every file. Archival backup saves time and storage space. 2. A backup that will be stored for a long time.
archival finding aids
Metadata tools such as indexes, guides, and inventories; these tools are often used by libraries, museums, and other institutions.
archive
1. To transfer files off the computer into long-term storage. Archived files are often compressed to save space. 2. A file that has been archived. 3. A group of files which must be extracted and decompressed in order to use them; software to be installed sometimes comes in this format. 4. A file stored on a computer network, which can be retrieved by FTP or other means.
archive site
A computer where stored files are available for download via the Internet. Archive sites may be accessed by anonymous FTP, Gopher, World Wide Web, or other services.
ARCMac
A Macintosh utility for decompressing files that have the .arc extension. Usually these are from older operating systems.
ARCNET
(Attached Resource Computer Network). A local area network (LAN) introduced in 1968 by Datapoint Corporation. It can connect up to 255 nodes in a star topology, using twisted pair or coaxial cable. ARCNET is a data linkprotocol and uses the token passing access method.
www.ardis.com, ARDIS started out as a joint venture between Motorola and IBM to provide wireless data transmission in the 800 MHz FM Band. The first wireless data network in the U.S., ARDIS was acquired by Motient in 1998, the first and largest two-way wireless data network with satellite communication in the U.S.
area code
A three digit telephone number prefix which indicates a specific calling area.
arg
Argument. A value that is passed to a program, subroutine, procedure, or function by the calling program; one of the independent variables that determine the output.
argument
A value that is passed to a program, subroutine, procedure, or function by the calling program; one of the independent variables that determine the output.
www.arin.net. A non-profit organization founded in 1997, ARIN handles the registration and dispensation of Internet Protocal addresses in North and South America. Its European and Asian counterparts are Researux IP Europeens (RIPE) and Asian Pacific Network Information Center (APNIC).
Advanced RISC Machine. One of a number of 32-bit RISC microprocessors for computing, games, multimedia, and many other uses. They are energy-efficient and economical.
ARP
Address Resolution Protocol. A method for finding a host's Ethernet address from its Internet address. An ARP request is sent to the network, naming the IP address; then the machine with that IP address returns its physical address so it can receive the transmission.
ARPA
Advanced Research Projects Agency. An agency of the U.S. Department of Defense that developed technology for the military. ARPANET, which was one of its projects, grew into the Internet.
ARPANET
Advanced Research Projects Agency Network. A Wide Area Network (WAN) developed in the 1960s by the Advanced Research Projects Agency of the U.S. Department of Defense, that linked government sites, academic research sites, and industrial sites around the world. Later, the military communications part split off and was named MILNET. ARPANET was the testing ground and original backbone of the Internet.
ARQ
Automatic Repeat Request. A modem status signal indicated by a light on the modem; in cases of transmissions errors, the ARQ is a request to the sender to retransmit.
array
An ordered arrangement of data elements in one or more dimensions: a list, a table, or a multidimensional arrangement of items. A vector is a one-dimensional array; a matrix is a two-dimensional array. Multidimensional arrays are used to store tables of data, especially in scientific simulation and mathematical processing. Data items in an array are distinguished by subscripts.
arrow keys
The keys on the keyboard that have arrows on them: up arrow, right arrow, left arrow, down arrow. They are used to move the cursor in the indicated directions, and have other uses in combination with other keys.
article
1. A news, magazine, or e-zine story. 2. A contribution to a Usenet discussion group, which can be sent by e-mail.
artificial intelligence
(AI). Intelligence that mimics human intelligence, when exhibited by devices and applications such as robots or computers with voice recognition and language processing ability. This human-like intelligence implies the ability to learn or adapt through experience.
artificial life
The study of synthetic systems to see in what way they behave like natural living systems. Artificla computer-generated systems are used to model the behavior of biological systems, including possible long-range outcomes of environmental changes. Some fields this study has been applied to are evolution, robotics, and engineering.
artificial neural network
(ANN). A network of many simple processors that imitates a biological neural network. Neural networks have some ability to “learn” from experience, and are used in applications such as speech recognition, robotics, medical diagnosis, signal processing, and weather forecasting.
artificial reality
Same as virtual reality. A computer simulation of reality, using 3D graphics and sound effects, with user interfaces such as special goggles and gloves, to create a lifelike environment for entertainment, experimentation, and training.
The part of a lowercase character that rises above the main body of the character. Lowercase d, b, and h have ascenders; u, m, and n do not.
ASCII
American Standard Code for Information Interchange. A code in which each alphanumeric character is represented as a number from 0 to 127, translated into a 7-bit binary code for the computer. ASCII is used by most microcomputers and printers, and because of this, text-only files can be transferred easily between different kinds of computers. ASCII code also includes characters to indicate backspace, carriage return, etc., but does not include accents and special letters not used in English. Extended ASCII has additional characters (128-255).
ASCII art
The drawing of pictures and designs on a computer, using only ASCII characters. ASCII art appears a lot in text-based media, where other graphic images cannot be shown. Many e-mail signatures include an ASCII art image.
ASCII characters
American Standard Code for Information Interchange characters. ASCII is a 7-bit binary code for 128 characters, which include alphanumeric characters, punctuation marks, and control codes such as the end of line character. ASCII is the built-in character set in most minicomputers and all personal computers. Together with the original 128 characters, 128 more characters can be added for an extended set of 256 characters. The second 128 characters are usually foreign language accents, math or graphics symbols, and other special symbols, but are not the same on all computers; DOS and Windows have different standard sets, and the Macintosh allows users to define the second 128 characters. Other character sets include extended ASCII, ANSI, EBCDIC, and Unicode.
ASCII file
American Standard Code for Information Interchange file. A file whose data is in ASCII characters. An ASCII file does not include formatting such as bold, italic, centered text, etc. Each byte in the file is one ASCII character, represented as a number; for example, capital H is ASCII 72. Some ASCII files contain program source code, scripts, or macros written as text. ASCII files are useful in transferring text between files of different formats that can’t be imported into each other. An ASCII file can be created with a text editor; some word processing programs, such as XyWrite and Microsoft Word, can also create ASCII files.
ASCII protocol
A communications protocol that transmits only ASCII characters and uses ASCII control codes. It is the simplest communications protocol and demands little, if any, error checking.
Ashton-Tate
The original developer of dBASE. In 1991 Borland International, Inc. took over Ashton-Tate.
ASIC
Application-Specific Integrated Circuit. A customized microchip which is designed for a specific application.
askSam
A PC text management system from askSam Systems, Perry, Florida.
ASL
Age, Sex, Location. This term is used to ask someone his or her age, gender, and place of residence. Most often it is the first thing someone will ask when you enter a chat room.
ASM
Association for Systems Management. An international organization which holds conferences for specialists in information systems management.
ASMO
Formerly MO7 (Magneto-Optic7) technology, Advanced Storage Magneto Optical is a rewritable optical disk technology that holds 7GB on a 12 cm disk.
ASMP
ASymetric MultiProcessing.
ASN.1
Abstract Syntax Notation One. The OSI language for describing abstract syntax.
ASP
1. Application Service Provider. A third-party software distribution and/or management service. Generally provides software via a wide area network from a centralized data center. Allows companies to oursource and more efficiently upgrade software. 2. Active Server Page. A specification for a Web page that is dynamically created by the Web server and contains both HTML and scripting code. With ASP, programs can be run on a Web server in a similar way to CGI scripts, but ASP uses uses the ActiveX scripting engine to support either VBScript or JScript. When a user requests data from an Active Server Page, the ActiveX server engine reads through the file, sends the HTML back to the browser and executes the script. Active Server Pages were first available on the Microsoft Internet Information Server (IIS) 3.0. They have the .ASP filename extension. 3. Association of Shareware Professionals. A trade association for shareware authors. Members submit shareware, which is tested and checked for viruses, then distributed on CDs.
Adaptec that allows application programs to access SCSI hardware. See SCSI.
Assembly language. The language in between machine language and high-level programming languages. Each statement in assembly code statement is translated into one machine code instruction.
(ACSE). OSI technology used to establish connections between applications.
http://info.acm.org/ Since 1947, the Association for Computing Machinery has been advancing information technology throughout the world. ACM offers chapters and activities, special interest groups, conferences and events, journals, magazines and films. ACM has Special Interest Groups (SIGs) in programming languages, software engineering, graphics, computer-human interaction, and more. Publications include Computing Reviews and the ACM Guide to Computing Literature, available online, and cover such topics as object technology, participatory design, internetworking, software project management, hypermedia, and wireless computing. ACM also recognizes important contributors in the field of computing.
Association for Systems Management
(ASM). An international organization which holds conferences for specialists in information systems management.
(ACCU) A worldwide association of people who are interested in C, C++, and related programming languages.
Association of Lisp Users
(ALU). An international user group for the Lisp programming language.
Association of Personal Computer User Gr
(APCUG). A nonprofit organization dedicated to encouraging communication among different user groups, and between user groups and vendors.
Association of Shareware Professionals
(ASP). A trade association for shareware authors. Members submit shareware, which is tested and checked for viruses, then distributed on CDs. See also ASP.
AST Research, Inc.
A manufacturer of PCs and add-in memory boards in Irvine, California.
asterisk
ASCII character 42: * . Also called star. Often used for footnotes. Sometimes used to *surround* words that the writer wants to emphasize in online communication, to substitute for italics.
Astronomical Markup Language
(AML). A standardized format for exchange of metadata related to astronomy. This language will enhance the ability of astronomers to retrieve scientific data, and make it possible for humans and intelligent agents to use the same information. Humans can view AML documents by means of a Java AML browser; intelligent agents can use an Extensible Markup Language (XML) parser.
ASV
Adaptive Suspension Vehicle. An advanced walking robot that is 16 feet long, 10 feet high, and weighs 6,000 pounds. The ASV has six legs and can sprint at eight miles per hour and step over a four-foot wall.
asymmetric cipher
Same as public-key cryptography. A form of cryptography in which each user has a public key and a private key. Messages are sent encrypted with the receiver’s public key; the receiver decrypts them using the private key. Using this method, the private key never has to be revealed to anyone other than the user.
Asymmetric Digital Subscriber Line
(ADSL). A digital subscriber line (DSL) technology in which the transmission of data from server to client is much faster than the transmission from client to server. Whereas with HDSL (High-Speed Digital Subscriber Line), transmission is 784 kilobytes per second in both directions, with ADSL, the rate from client to server is 640 kilobytes per second and from server to client can be up to 6 megabits per second (Mbps). This kind of connection is useful with applications such as interactive TV and Video on Demand, because the data the server sends is much more than the data sent by the client. ADSL uses bandwidth that is not used by voice; therefore voice and data can be transmitted at the same time.
Asynchronous. Not synchronized by a common timing signal. In asynchronous communication, each character can be transmitted at any time and is distinguished by a start bit and stop bit; in synchronous communication the start and stop bits are not needed as there is a regular time interval between transmissions. With asynchronous terminals, a transmission can be initiated at either end.
asynchronous
(ASYNC) Not synchronized by a common timing signal. In asynchronous communication, each character can be transmitted at any time and is distinguished by a start bit and stop bit; in synchronous communication the start and stop bits are not needed as there is a regular time interval between transmissions. With asynchronous terminals, a transmission can be initiated at either end.
asynchronous transfer mode
(ATM). A type of fast packet switching that uses a fixed size packet called a cell. This technique makes it possible to transmit data at great speed, and can make voice, multimedia, full-motion video, and video conferencing available to all users. It also makes dynamic allocation of bandwidth possible; telephone and cable TV companies can charge individual customers based on the amount of bandwidth they use.
asynchronous transmission
A way of transmitting data in which one character is sent at a time, and there may be uneven amounts of time between characters. A start bit and a stop bit notify the receiving computer when the transmission begins and ends. In synchronous transmission, strings of multiple characters are transmitted; this method is faster, but more expensive.
AT
Advanced Technology. An IBMPC introduced in 1984 that was the most advanced PC at that time, with an Intel 80286 processor, 16-bit bus, and 1.2MB floppy drive.
AT command set
The commands used for Hayes and Hayes-compatible modems, which begin with the letters AT.
AT keyboard
Advanced Technology keyboard. The keyboard that originally came with the IBM PC/AT computers, which had 84 keys including the alphanumeric keys, the number pad, F keys, and arrow keys.
AT motherboard
Advanced Technology motherboard. The motherboard that originally came with the IBM PC/AT computers, or one following the same design.
at sign (@)
The at sign distinguishes the domain name from the recipient in an Internet e-mail address (i.e. for the address [email protected], james is the recipient and computeruser.com is the domain).
AT&T
American Telephone and Telegraph, Inc. One of the largest corporations and telecommunications carriers in the United States. AT&T has been incorporated since 1885, and has provided telephone service throughout the United States and in other countries. AT&T was parent company of the Bell System of telephone companies, a monopoly which was dissolved in 1984 by a Federal court order. AT&T continues to be a competitive long distance telephone carrier. AT&T has been credited with breakthroughs in technology, including the UNIXoperating system and the C and C++ programming languages. At&T can be found online at www.att.com.
ATA
Advanced Technology Attachment. The specification for IDE interface.
ATAPI
Advanced Technology Attachment Packet Interface. An interface used to connect CD-ROMs, tape drives, and optical disks with the computer.
Atari
A family of 16-bit and 32-bit microcomputers from Atari Computer, Sunnyvale, California, which became popular for games and for their MIDI interface. Some of the models are the Atari 520ST, 1040ST, Mega ST, STe, STacy, Mega STe, TT, and the Falcon. The Atari 2600, 5500 and 7800 were also popular.
ATDT
ATtention Dial Tone. One of the AT commands used with Hayes modems.
ATM
1. Asynchronous Transfer Mode, a network technology that enables the transmission of data, voice, audio, video, and frame relay traffic in real time. 2. Automatic Teller Machine, a bank terminal that lets customers deposit, withdraw cash, and perform other transactions electronically. 3. Adobe Type Manager, a software program that manages PostScript fonts on a system. 4. At The Moment (chat).
ATM Forum
Formed in 1991, this organization, which includes more than 750 companies, as well as research groups and government agencies, was founded in order to promote ATM technology, and set and accelerate standards.
ATM NIC
Asynchronous Transfer Mode (ATM) Network Interface Card (NIC). ATM NIC transmits or receives ATM commands and requests.
atomic
Indivisible. This word is used in computing to describe an operation which must be carried to completion or not performed at all.
attached processor
A processor that does not have Input/Output capability, and is attached to a processor that handles input and output.
1. A file linked to an e-mail message. Many mail programs use MIME encoding to attach files. 2. A device attached to a computer, along with any adapters used to attach it.
An open specification from Intel for a motherboard that is a further evolution of the Baby AT, giving more space for expansion slots and Input/Output. The motherboard is rotated 90 degrees in its chassis. The ATX supports multimedia and USB (Universal Serial Bus). In this design, the power supply blows air over the processor chip instead of pulling air through the chassis.
audio
Relating to the range of frequencies within human hearing, generally between 15Hz and 20,000 Hz cycles per second.
audio adapter
An add-on adapter card that improves a computer's sound quality, and adds other sound capabilities, sometimes including MIDI. An audio adapter makes it possible to use speakers, a stereo, and a microphone to record and play sound.
Audio Interchange File Format
(AIFF). A format developed by Apple Computer for storing high-quality sampled audio and musical instrument information. It can be played on PC and Mac, and is used by some professional audio software packages.
audio streaming
Playing audio immediately as it is downloaded from the Internet, rather than storing it in a file on the receiving computer first. Streaming is accomplished by way of Web browser plug-ins, which decompress and play the file in real time; a fast computer and fast connection are necessary.
Audio Video Interleaved
(AVI). A Microsoftmultimedia file format, similar to MPEG and QuickTime, used by Video for Windows. In AVI, audio and video elements are interleaved (stored in alternate segments) in the file.
audioconferencing
Teleconferencing using sound for communication between participants.
audiographic teleconferencing
A form of teleconferencing in which a voice connection and an electronic whiteboard are used to communicate ideas between participants.
AUG
Amiga User Group.
AUI
Acronym for Attachment Unit Interface, a device that contains a 15-bit pin, or socket, and is used to connect a Network Interface Card (NIC) with a standard Ethernet cable.
AUP
Acceptable Use Policy. A policy which limits the way a network may be used; for instance, some networks are restricted to noncommercial use.
AUSCERT
The Australian Computer Emergency Response Team.
authentication
Verification of identity as a security measure. Passwords and digital signatures are forms of authentication.
authoring
Creating a document; especially used for World Wide Web documents.
authoring language
A high-level application which helps non-programmers to create tutorials and courseware.
authoring program
A program that helps in the creation of interactive courseware.
authoring system
A collection of tools which can be used by non-programmers to create interactive applications.
authorization code
A set of characters or password giving a user access to a remote or local computer network.
A CAD program for mechanical engineering from Autodesk, Inc., which can be run on PC, Macintosh, UNIX, and VAX.
AUTOCODER
An early compiler for the Manchester Mark I computer.
AUTODIN
Abbreviation for AUTOmatic DIgital Network, the U.S. Defense Communication System's global communications network.
AUTOEXEC.BAT
(Automatically Executing Batch File). A DOS batch file that is executed automatically when the computer is started, after CONFIG.SYS is run. AUTOEXEC.BAT sets up the DOS prompt, tells the system which directories to search for programs to run, loads the mouse driver, configures the serial ports, and initializes RAM-resident programs and utilities. AUTOEXEC.BAT can be custom configured by the user, and may be used to configure network connections, or to load a particular application program on startup. New software packages often make automatic changes to AUTOEXEC.BAT upon installation. Windows 95 will use AUTOEXEC.BAT if it is present, but does not usually need it.
autoflow
A function of some programs that allows text to wrap around graphic images and spread from one page to the next, to fill the space as needed.
(Plural of automaton). Machines, robots, or systems which follow a preset sequence of instructions automatically.
automata theory
The study and invention of automata.
automatic baud rate detection
(ABR). The process in which a receiving device examines the first character of an incoming message to determines its speed, code level, and stop bits. Having this automatic function makes it possible to receive data from different transmitting devices operating at different speeds without having to establish data rates in advance.
automatic number identification
(ANI). A service that identifies the telephone number of each incoming telephone call.
automatic repeat request.
(ARQ). A modem status signal indicated by a light on the modem; in cases of transmissions errors, the ARQ is a request to the sender to retransmit.
Automatic Teller Machine
(ATM). An automated banking terminal where customers can deposit and withdraw cash by means of a magnetic ATM card. See also ATM.
automation
The automatically controlled operation of an apparatus, process, or system by mechanical or electronic devices that replace human control.
automaton
A machine, robot, or abstract device which performs tasks by following automatically a predetermined sequence of instructions. Some automata mimic human behavior.
Autonomic Computing
A term coined by IBM to describe their vision about the future direction of computing. Analogizing it to the autonomic functions that take place in a human’s central nervous system, autonomic computing would be comprised of networks that are “self managing, self diagnostic, and transparent to the user.” IBM sees it as a paradigm shift in thought, as computers would be defined less by computational speed, and more by the ability to access information.
A program that automatically delivers information by e-mail. Also called a mailbot.
autosave
A function of some programs which save data to the disk at periodic intervals, without being given a Save command. In the Preferences menu, the user can set up the autosave function and tell the program how frequently to save.
AutoSPID
(Automatic Service Profile Identifier). SPID is the identification number for connecting to an ISDN (Integrated Services Digital Network) line. AutoSPID is a protocol an ISDN device uses to automatically negotiate the number with the switch without the need for user interaction.
AUX
Auxiliary device. A peripheral device that may perform a useful function but is not necessary for the operation of the computer. Examples are printers, scanners, and modems.
auxiliary device
(AUX). A peripheral device that may perform a useful function but is not necessary for the operation of the computer. Examples are printers, scanners, and modems.
auxiliary memory
An additional memory bank in a supercomputer or mainframe, which is accessed via a high-bandwidth channel.
auxiliary storage
Storage on external media such as disk or tape.
AV
1. Audio/Video. 2. Audiovisual.
avatar
A pictorial representation of a participant in a three-dimensional chat environment. The avatar is chosen by the user and may look like a bird, a fish, or some other colorful character.
Average Access Time
(AAT) The average amount of time it takes for a storage peripheral to transfer data to the Central Processing Unit (CPU).
AVI
Audio Video Interleaved. AVI is a Microsoft multimedia file format, similar to MPEG and QuickTime, used by Video for Windows. In AVI, audio and video elements are interleaved (stored in alternate segments) in the file.
AVR
Automatic Voice Recognition.
AWE
1. Advanced WavEffects. A series of sound cards from Creative Labs that includes the Sound Blaster AWE 32, the Sound Blaster AWE64, and the AWE64 Gold. The AWE64 can play in 64 voices at the same time using Wave-Table synthesis, and has Plug and Play installation. 2. The Advanced WavEffects engine used with the AWE sound cards.
AWG
American Wire Gauge.
AWGTHTGTTA
Are We Going To Have To Go Through This Again?.
AWHFY
Are We Having Fun Yet?.
awk
An interpreted language for Unix and DOS developed by Alfred Aho, Peter Weinberger, and Brian Kernighan in 1978. The name is based on the initials of the three developers.
AWT
Abstract Windows Toolkit. A Java application programming interface that allows programmers to develop Java applications having graphical user interface, which are usable on a variety of platforms such as Windows, Macintosh, and UNIX. The AWT instructions are translated for the host operating system by Java Virtual Machine (JVM).
AX
Architecture eXtended.
axis
One of the intersecting reference lines in a coordinate system. Axes are used to plot numbers on a chart or specify the location of a point on a line, on a surface, or in space. The horizontal axis is designated as the x axis, the vertical axis is designated as the y axis, and if a third dimension of depth is indicated, it is called the z axis.
AYT?
Are you there?
AZERTY keyboard
The first six letters in the keyboard layout used in some European typewriters. See QWERTY keyboard.
b
Bit. Short for binary digit. The smallest unit of information a computer can hold. The value of a bit is 1 or 0.
B
Byte. The smallest addressable unit of storage; the amount of memory space used to store one character, which is usually 8 bits. A computer that has 8-bit bytes (most large and small computers today) can distinguish 28 = 256 different characters. See bits, kilobytes and megabytes.
B channel
On an ISDN (ISDN), a connection that provides voice and data at the same time.
Business to business electronic commerce. Businesses conducting transactions with one another via the World Wide Web.
B4
Before. Variant: b4
Babbage, Charles
(1791-1871) A British inventor of computing machines, known as the “Father of Computing” for his contributions. Babbage invented a “difference engine,” which was a device for producing mathematical tables. His “analytical engine” introduced ideas that were later used in electronic computers. Babbage was the first to have the idea of a machine which could be run by a program stored in its memory.
A means of disabling a system's security which is deliberately left by designers of the system, often to give access to service technicians or maintenance programmers.
back end
A computer that does the main processing but has a smaller, more friendly computer that the user interacts with (called the front end). 2. A program that takes care of details behind the scenes, performing tasks not directly controlled by the user.
Back Orifice
A hostile application which can be used by a cracker to take remote control of a computer. It appeared in the summer of 1998, then was quickly brought under control by anti-virus and security software programs; the application left a clear 120,000-byte signature.
back up
To make copies of important files in case the originals are damaged. Data can be backed up on external hard drives, floppy discs, CD-ROMs, tape, etc.
backbone
In a hierarchical network, the backbone is the top level, employing high-speed data transmission and serving as a major access point; smaller networks connect to the backbone.
background
The color or pattern on a computer screen which is behind the text and graphic elements.
background noise
Interference in the form of extra signals in a line or circuit.
background task
A task that runs on its own while the user interacts with the computer on another (foreground) task; for example, some computers can run a printer in background while the user edits text or reads other files.
backing up
Making copies of important files in case the originals are damaged. Data can be backed up on external hard drives, floppy discs, backlit
Illuminated from behind; this kind of illumination is used in the LCDs on laptop computers.
backout
The elimination of updates made in a transaction that was interrupted by a system failure.
backslash
The character (ASCII 92), not to be confused with the forward slash / (ASCII 47).
backspace
To move the screen cursor to the left, using the “backspace” or “delete” key, depending on keyboard layout. On a typewriter, a backspace simply moves the carriage back one character or space; on a computer, backspacing deletes the character.
backspace key
A keyboard key that moves the screen cursor to the left, sometimes called the delete key. On a typewriter, a backspace simply moves the carriage back one character or space; on a computer, the backspace key deletes the character.
backup copy
An extra copy of a file kept for safety.
backward-compatible
A backward-compatible version of software is able to coexist with older versions that may have been installed on the machine previously, and able to read files of the older version. Also called downward-compatible.
Bad command or file name
An MS-DOS error message that means it is unable to execute the command as given, or cannot find the desired file or program.
bad disk
A floppy disk that can no longer store information reliably, perhaps because of physical damage.
bad sector
Sectors are pie-sliced divisions of a disk. A bad sector means part of the disk is physically damaged and that data cannot be read from or written to that sector. Sometimes data that is lost because of bad sectors can be restored with utility programs designed for the purpose; if this fails, sometimes special hardware can be used to recover it.
ball printer
A printer that has a metal print head shaped like a ball, with raised characters around its surface. To print, the printer rotates the ball into position to strike each character against a ribbon.
balloon help
A Macintosh help feature that displays a cartoon balloon next to objects on the screen when the user points to them with the cursor. A message in the balloon explains what each feature does and how to use it. The balloons can be turned on and off as needed.
BALUN
BALanced UNbalanced (device).
band
A defined range of frequencies used for transmitting a signal. See also bandwidth.
bandwidth
1. The amount of data that can be sent through a network connection, measured in bits per second (bps). 2. The range of transmission frequencies a network can use, expressed as the difference between the highest and lowest frequencies of a transmission channel (in Hertz, or cycles per second).
High bandwidth allows fast transmission or high-volume transmission.
Old-style UUCP email addresses used an exclamation point to indicate each station through which the mail passed on its way to the addressee. They were named “bang paths” because “bang” means exclamation point.
A graph that uses bars to represent the information provided.
bar code
A pattern of bars of various widths and with varying spaces between them, printed on paper or similar material for recognition by a scanner that uses a laser beam or a light source and photocell. Bar codes are used by the U.S. Post Office to encode mail, in stores to price items with the UPC (Universal Product Code), and for many other purposes.
bar printer
A kind of impact printer in which the character slugs are moved on a type bar.
bare bones
Having only the most essential elements; no frills. Computer ads often use this word to describe basic hardware systems.
base 10
Decimal; the numbering system in common use, in which each place to the left or right of the decimal represents a power of 10. The base 10 numbering system uses the numerals 0 to 9. The number one-hundred twenty, for example, is written 120 (1 in the hundreds place, 2 in the tens place, and 0 in the ones place). Computer languages use binary, or base 2, and hexadecimal (base 16), rather than decimal numbers.
base 16
The hexadecimal numbering system, sometimes used as a short way of representing binary numbers. The digits 0-9 are used, plus the letters A-F which stand for numbers 10 through 15. The farthest-right digit is the ones place; the digit next to the left is the 16s place; the next place to the left is 16^2 = 256, etc. Each place is 16 times the place immediately to the right of it. For example, the decimal number 18 would be represented as 12 (1 in the 16s place, 2 in the ones place) in base 16. Hexadecimal (base 16) numbers are often written with the letter h after them; for example, 13h.
base 2
The binary numbering system, which has 2 as its base and uses 0s and 1s for its notation. Binary code is used by computers because it works well with digital electronics and Boolean algebra. The number one in base 2 is written as 1. The number two is written as 10 (1 in the twos position and 0 in the ones position). The numbers three to ten in base 2 are written: 11, 100, 101, 110, 111, 1000, 1001, 1010.
base 8
Also called the octal numbering system. Base 8 numbers use only the digits 1, 2, 3, 4, 5, 6, 7; the second column to the left is the 8s place. For example, 36 in base 8 is 6 ones and 3 eights, or 30 decimal. Base 8 notation can be used as a shortcut for representing six-bit binary (base 2) characters by converting each three bits into one base 8 digit, this way: 011 010 binary = 32 octal = 26 decimal (base 10).
base address
Part of a memory address that is used as a reference point for other addresses, called relative addresses. Base addresses are referred to as segment addresses in IBMPCs and PC compatibles. See also ablsolute address.
baseband
A network technology that uses a single-carrier frequency and is used for short-distance transmission. The complete bandwidth of the channel is used. If more than one message at a time is transmitted, the messages must be interleaved, a technique called time division multiplexing. Contrast broadband.
baseline
Where the bottoms of characters in a line of type (excluding descenders) line up. Typesetters measure leading from baseline to baseline.
baseline to baseline
(B/B or b/b) From the bottom of a line of type to the bottom of the next line of type (excluding descenders), used as a measurement of leading.
Basic
Beginner's All-purpose Symbolic Instruction Code. A simple programming language designed in 1963 by John Kemeny and Thomas Kurtz at Dartmouth College. Basic was designed as an easy programming language to learn. Beginners can quickly learn to write simple programs. Originally for mainframes, it is now extensively used on personal computers.
Abstract Syntax Notation One (ASN.1).
ROM chip inside IBM PCs and PC-compatibles, which handles all input-output functions. See also BIOS.
Basic language
Beginner's All-purpose Symbolic Instruction Code language. A simple programming language designed in 1963 by John Kemeny and Thomas Kurtz at Dartmouth College. Designed as an easy programming language to learn, beginners can quickly learn to write simple programs. Originally for mainframes, it is now extensively used on personal computers.
Basic Network Utilities
(BNU). An IBM set of utilities that make it possible for a user to communicate with AIX and UNIX systems via telephone connections or dedicated lines.
On an internal network, the only host which is visible to the Internet through the firewall.
batch
A group of items. In computing, a batch system is one that executes a series of commands which are all given before the program starts to run, instead of an interactive system which requires the user to give commands during the operation.
batch file
A file containing a series of commands for the operating system which are executed automatically in sequence. In DOS, batch files end with .BAT. In UNIX, they are called shell scripts.
batch processing
Processing a group of documents or files all at once. In batch processing, the user gives the computer a job, for example, printing letters to everyone on a mailing list, and waits for the whole job to be done. During the batch job, the user does not interact with the computer. In interactive processing, the user communicates with the computer while the program is running, perhaps giving instructions for each item.
batch session
A session in which an entire file is transmitted or updated without interruption, as opposed to an interactive session which requires input from the operator. See batch system
A system that executes a series of commands which are all given before the program starts to run, instead of an interactive system which requires the user to give commands during the operation.
BatteryMark
A benchmark from Ziff-Davis that measures battery life on notebook computers running Windows 95. It must be run with special hardware, the ZDigit II.
baud
A unit of measure of transmission speed. Named after J.M.E. Baudot (1845-1903), French engineer. Originally baud was used for telegraph transmissions, and meant one Morse code dot per second. Baud is a measure of the number of signal-state changes per second; for example, voltage or frequency changes. It is sometimes, but not always, the same as the number of bits per second.
baudy language
The combination of letter abbreviations (such as IMHO) and emoticons ( :-) ) used in e-mail, chat rooms, and other forms of online communication.
bay
A shelf within a computer case for a hard drive, CD-ROM drive, tape drive, floppy drive, etc. The more bays in a case, the more drives can be added.
bayonet mechanism
The mechansim found in the BNC connector. BNC stands for Bayonet Neill Concelman. Bayonet denotes the coupling mechanism, while Neill and Concelman were the inventors of the N and C connectors. Thus, the bayonet mechanism is a method by which the N and C connectors come together in the BNC connector.
BBC Educational Text to Speech Internet
BETSIE. A software package designed to help blind and visually impaired people surf the Net, from British Broadcasting Corporation’s BBC Education Online.
BBN
Bolt, Beranek and Newman, Inc. A Cambridge, Massachusetts, company which was awarded the original contract to build ARPANET and subsequently has been involved in many aspects of Internet development. 2. In chat, Bye Bye Now
BBS
Bulletin Board System. A computerized version of the bulletin boards found in stores and other public places, where people can leave messages and advertise things they want to buy or sell. BBSs are often run by local computer user groups, and offer downloads of shareware and freeware plus online information and services. There are special interest bulletin boards, including those run by computer companies to provide information on their products. Many BBSs now have web pages.
2. In chat, Be Back Soon
BCC:
Blind carbon copy. Sending a copy of a letter to another person in addition to the addressee, without showing on the original letter that a copy was sent to someone else.
BCD
Binary Coded Decimal. A binary-coded notation in which each of the decimal digits is expressed as a binary numeral; for example, in binary-coded decimal notation 12 is 0001 0010, as opposed to 1100 in pure binary.
(BITNET). An academic computer network originally connecting IBMmainframes and VAX systems via leased lines, providing electronic mail, file transfer, electronic mailing lists, and other services. BITNET merged with CSNET, The Computer+Science Network, and became part of CREN, The Corporation for Research and Educational Networking.
beep
A sound emitted by the computer to indicate that something requires the user's attention.
BeIA
This is an operating system (OS) developed by Be Inc. It is designed to run on Internet Applicances and Entertainment Applicances, and touts extremely stable multimedia capabilities, compatibility with most popular Web plug-ins, and the flexibility to conform to the needs of its users (whether they are savvy web surfers, beginners, or Information Technology (IT) professionals).
bell character
The control code (ASCII character 7) which causes an alert bell or tone to sound on the computer.
Bell Laboratories
AT&T's research and development center in Murray Hill, NJ.
Bell Operating Company
(BOC). Also called RBOC for Regional Bell Operating Company. There is a BOC for each of seven regions of the United States.
Bellcore
Bell Communications Research, Inc. A research laboratory for the seven regional Bell Telephone companies in Livingstone, NJ.
bells and whistles
Fancy features added to software or hardware; usually indicates features that are more flashy than practical.
Bench32
A comprehensive benchmark that measures overall system performance under Windows NT or Windows 95.
benchmark
A standard test which is run on a computer, a peripheral device, or a program to give a measure of its performance. Benchmarks are criticized because they can be misleading. The best test of a computer's performance is to test a computer with the exact configuration and doing the same tasks the user intends to do. Many computer magazines put new machines through a series of benchmark tests and compare them.
benign virus
A virus that does not destroy programs or data, but displays a message, perhaps a humorous one, on the computer screen at certain times; intended as a harmless prank.
BeOS
The operating system of the BeBox personal computer, designed by Be Inc. It has a graphical user interface, and supports multitasking and real-time operation. It can be downloaded for free for personal use from Be Inc's homepage, and installed under Windows 95 or 98. Once installed, the OS can be run by simply double-clicking on its Windows icon. Thereafter, the OS exits windows and reboots the system from a large file in the FAT file system. See also BeIA.
BER
1. Basic Encoding Rules. The rules for encoding data described in Abstract Syntax Notation One (ASN.1). 2. Bit Error Rate. The estimated average number of bits sent in error.
Berkeley Internet Name Domain
(BIND). A DNS server implementation developed by the University of California at Berkeley.
Berners-Lee, Tim
Inventor of the World Wide Web. Born in England, he graduated from Queen's College at Oxford University, England, in 1976. While there he built his first computer. In 1984, he took up a fellowship at CERN, the European Particle Physics Laboratory, as a software engineer. Looking for a way to improve communications among the High Energy Physics community, Berners-Lee wrote a proposal in 1990 for a hypertext project. The result of this project was HyperText Markup Language (HTML), the common language of the Web. He wrote the first World Wide Web server, HTTPd, and the first client, WorldWideWeb, a hypertext browser and editor which ran in the NeXTStep environment. This program became available on the Internet in 1991. Berners-Lee had written the software in less than two months, and gave it away free. Less than five years later, more than 6 million people were using it. In 1994, Berners-Lee began working at the Laboratory for Computer Science at MIT (Massachusetts Institute of Technology). He also directs the World Wide Web Consortium (W3C), a standards group whose goals are to realize the full potential of the Web and ensure its stability.
(1872-1970) The English philosopher, author, and mathematician who discovered Russell's paradox: “If the barber of Seville shaves all men in Seville who don't shave themselves, and only those men, who shaves the barber?”
beta
1. A new or revised software version released for beta testing. Typically the beta version will have most if not all of the features the finished product is scheduled to include. 2. The Sony VCR format, later replaced by VHS as the standard for home and industry.
beta testing
The second stage in testing new software: making it available to selected users, who try out the software under normal operating conditions, in the kind of environment in which it will be used. See also beta.
betaware
Software that is given to many users for beta testing before its official release. See also beta and beta testing.
BETSIE
(BBC Educational Text to Speech Internet Enhancer). A software package designed to help blind and visually impaired people surf the Net, from British Broadcasting Corporation’s BBC Education Online.
Bezier
This is used in computer graphics. It describes a curve which is produced from a mathematical formula that ensures that the cure will not be interrupted by other Bezier curves.
Bezier curve
Also called Bezier spline. A curve made of a line that is set up to connect two points, but has two other points that influence the shape of the line by “pulling” it toward them into a curve. In computer drawing programs, curves are made by moving onscreen “handles” to adjust the curve’s shape, thus creating a Bezier curve. Bezier curves are named after Pierre Bezier, who discovered the mathematical formula.
Bezier spline
Also called Bezier curve. A curve made of a line that is set up to connect two points, but has two other points that influence the shape of the line by “pulling” it toward them into a curve. In computer drawing programs, curves are made by moving onscreen “handles” to adjust the curve's shape, thus creating a Bezier spline. Bezier splines are named after Pierre Bezier, who discovered the mathematical formula.
Broadcast Hypertext Markup Language. A markup language based on XML, designed for synchronization of digital television, data, and Internet technologies.
bi-endian
Able to work in either big-endian or little-endian mode, or switch back and forth. An example is the PowerPC processor. See big-endian, little-endian.
BibTeX
LaTeX bibliography software.
bidirectional
Going in two directions.
bidirectional printer
A printer that prints a line from left to right, then the next line from right to left, etc.
Big Blue
The nickname for IBM, based on the color of its logo.
big-endian
A binary data format in which the most significant bit comes first.
bignum
A way of representing very large integers in some computer languages, so that calculations can be made with them.
billion
10^9 (U.S. and Canada); 10^12 (Europe).
binary
A system of numbers having 2 as its base and using 0s and 1s for its notation. Binary code is used by computers because it works well with digital electronics and Boolean algebra.
binary file
A file that contains codes that are not ASCII characters. A binary file could be a file with executable machine language code. Binary files must be encoded in order to transmit them over a network, and decoded on the receiving end. BinHex and uuencode are two programs which can be used to encode binary files.
Binary Large Object
(BLOB). A database field that can hold images, audio, video, long text blocks, or any digitized information.
binary number
A number represented in binary form; for example, the number 101 in binary notation is the same as 5 in decimal notation.
binary-coded decimal
(BCD). A binary-coded notation in which each of the decimal digits is expressed as a binary numeral; for example, in binary-coded decimal notation 12 is 0001 0010, as opposed to 1100 in pure binary.
A format in which Macintoshbinary files are temporarily encoded as ASCII files for transmission over the Internet. The Internet was originally designed for transferring text messages (7-bit files) from one computer to another. Binary files are 8 bits wide. An 8-bit file transmitted over the Internet can lose one-eighth of its data. BinHex encoding puts the 8-bit wide file into a 7-bit text format. Also, Macintosh files have a resource fork and a data fork; the resource fork is normally lost when a file is converted to a 7-bit format. BinHex preserves the resource fork, as well as the data fork, in Macintosh files. The BinHex format is not a compression format; it makes the file larger, and a file encoded in BinHex format will take longer to transmit. BinHex also converts the file back into its original format after transmission. The filename extension for BinHex files is .hqx. See also Macintosh file, MacBinary.
Bioinformatic Sequence Markup Language
(BSML). A proposed public domainprotocol for Graphic Genomic Displays, based on SGML and XML. The purpose of BSML is to communicate genetic information more easily. BSML is funded by the National Center for Human Genome Research.
biometric security
A way of authenticating the identity of an individual by using fingerprints, palm prints, retinal scans, or other biological signatures.
bionet
Top-level newsgroup category for a biology newsgroup.
BIOS
Basic Input/Output System. A set of instructions stored on a ROM chip inside IBMPCs and PC-compatibles, which handles all input-output functions.
(BOF). An informal discussion group on a particular topic, heard especially in connection with USENIX.
bis
Second (in French); “bis” indicates the second release of a standard. For example, in modem data transmission, V.22bis, V.32bis, etc.
BISDN
Broadband Integrated Services Digital Network. A high-speed telecommunications service which can transmit multimedia over the phone line. It uses fiber-optic cable and synchronous transfer mode, and is faster than narrowbandISDN. BISDN can be used for voice, data, fax, e-mail, full motion video, and video conferencing.
bit
1. (b). Short for binary digit. The smallest unit of information a computer can hold. The value of a bit is 1 or 0. 2. Top-level newsgroup category for a BITNET mailing list newsgroup.
bit depth
In bitmap graphics, the number of bits per pixel; the idea of bit depth can also be applied in storing other kinds of information. The number of bits per pixel determines the number of shades of gray or variations of color that can be displayed by a computer monitor. For example, a monitor with a bit depth of 1 can display only black and white; a monitor with a bit depth of 16 can display 65,536 different colors; a monitor with a bit depth of 24 can display 16,777,216 colors. See 4-bit color, 8-bit color, 15-bit color, 16-bit color, 24-bit color, 32-bit color.
Bit Error Rate
(BER). In fiber optics, the ratio of the number of bits received incorrectly to the number of bits transmitted.
bit level device
A device whose input and output are in the form of data bits. Contrast pulse level device.
bit manipulation
Low-level programming that works with individual bits.
bit rate
The speed at which bits are transmitted, in bits per second. Also called data rate.
bit-oriented protocol
A communications protocol in which the control codes are individual bits rather than bytes.
bitmap
An image or other collection of data represented as an array of bits. In bitmap graphics, an image is displayed on the screen as a collection of tiny squares called pixels, which together form a pattern. Each pixel in the image corresponds with one or more bits; the number of bits per pixel determines how many shades of gray or colors can be displayed. “Bitmap” is used to refer to both the image itself and the file that holds the data for the image. See bitmapped font, bitmap display, bitmap graphics, bit depth.
bitmap display
A computer display in which each pixel onscreen is mapped to one or more bits in memory. Images are generated on the screen as the bit pattern to be displayed is written into video memory. Most current personal computers have bitmap displays, which allow the fast updating of images necessary for graphical user interfaces.
bitmap graphics or bit-map graphics
A way of displaying images on a computer screen in which each picture is represented as an array of little squares called pixels. Each pixel is stored in a specific location in memory, and corresponds to one or more bits. The number of bits per pixel determines the number of colors or shades of gray that can be displayed. Bitmap graphics can be created and edited in paint programs or photo editing programs, and can be stored in a number of file formats. Depending on file format, bitmap graphics can sometimes be imported into word processing, page layout, or spreadsheet programs, or incorporated in World Wide Web pages. Same as raster graphics; contrast vector graphics.
bitmapped font
A font in which each character is formed from pixels arranged to make the shape of the character. Such an arrangement of pixels is called a bitmap.
bitmapped graphics
A way of displaying images on a computer screen in which each picture is represented as an array of little squares called pixels. Each pixel is stored in a specific location in memory, and corresponds to one or more bits. The number of bits per pixel determines the number of colors or shades of gray that can be displayed. Bitmapped graphics can be created and edited in paint programs or photo editing programs, and can be stored in a number of file formats. Depending on file format, bitmapped graphics can sometimes be imported into word processing, page layout, or spreadsheet programs, or incorporated in World Wide Web pages. Same as raster graphics; contrast vector graphics.
BITNET
Because It's Time Network. An academic computer network originally connecting IBMmainframes and VAX systems via leased lines, providing electronic mail, file transfer, electronic mailing lists, and other services. BITNET merged with CSNET, The Computer+Science Network, and became part of CREN, The Corporation for Research and Educational Networking.
bits per inch
(bpi). A measurement of the recording density of a tape or disk.
bits per second
(bps). The rate of data transfer over a communication line. The data rate of a modem is measured in kilobits per second.
bitwise
Working on the level of bits rather than bytes or larger units.
bitwise operators
Programming statements that work on the level of bits.
BIX
Byte Information Exchange. An online computing database from Byte magazine, providing technical support for computer users and information on hardware and
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biz
Top-level newsgroup category for a business newsgroup.
black widow
A harmful computer program which is downloaded from the WWW as a Java applet.
blank character
ASCII character 32: space bar. The character for the space bar takes up one byte in the computer the same as any other character.
BLAST
BLocked ASynchronous Transmission protocol (CRG).
bleed
Printing in which the ink extends to the very edge of the paper, usually done by printing on a wider sheet of paper, and cutting it down to the correct size.
blind carbon copy
(BCC:). Sending a copy of a letter to another person in addition to the addressee, without showing on the original letter that a copy was sent to someone else.
bloatware
Software that uses excessive memory in proportion to the task it performs, perhaps because of having too many unnecessary features.
BLOB
Binary Large Object. A database field that can hold images, audio, video, long text blocks, or any digitized information.
blue laser
A laser that uses a blue-light emitting diode, based on gallium nitride. Using a blue laser, optical and magneto-optical disks can be produced with a much greater recording density than disks made with infrared lasers.
blue screen of death
An error that sometimes appears on computers running Windows 95 or Windows NT; the screen turns blue, and the computer usually freezes.
Bluetooth
An evolving short-range networking protocol for connecting different types of devices; for example, connecting a mobile phone with a desktop or notebook computer, accessing the Internet via the phone's mobile data system, and even linking the user's voice to the computer. Bluetooth devices can communicate by wireless signals within a 35-foot range, and do not need a line-of-sight connection. Products based on Bluetooth technology will include mobile computers, mobile phones, handheld devices, and peripherals such as headsets and network access points. Other potential uses of Bluetooth are LAN access devices enabling users to switch on a notebook and get on the office network without connecting to an Ethernet cable, devices for telephone and ISDN connections in the home, and embedded technology for use in GSM handsets.
BMP
File extension used for raster graphics stored in bit map format.
BNC
British Naval Connector. A plug and socket connector used most often with coaxialEthernet cable. The connector is first inserted into the socket, then turned to lock tight by means of a bayonet mechanism . BNC connectors are used in many applications, some of which are flexible networks, instrumentation and computer peripheral interconnections.
BNC T-connector
(British Naval Connector T-connector.) A metal connector shaped like the letter T, which is used with coaxial cables on a 10Base2 network. The ends that form the top of the T connect with network cables, and the other end plugs into the external end of a network card on the back of the computer.
Basic Network Utilities. An IBM set of utilities that make it possible for a user to communicate with AIX and UNIX systems via telephone connections or dedicated lines.
Breakout Box. A testing device for multiple line cables that makes a connection to each line to see if a signal is present.
BOC
Bell Operating Company. Also called RBOC for Regional Bell Operating Company. There is a BOC for each of seven regions of the United States.
BOF
1. Beginning Of File. 2. Birds Of a Feather. An informal discussion group on a particular topic, heard especially in connection with USENIX.
boilerplate
Material that is copied and used over and over; for example, a letterhead or copyright notice. Text (or logos, etc.) set up once, then saved and reused in many documents.
bold italic
Bold italic type has the italic script design but the extra weight of boldface letters and is used for emphasis in typography.
boldface
Boldface, or bold, type characters are thicker and darker than normal text. Most standard type fonts can be made bold in programs that handle type styling, such as word processors, page layout programs, and graphic design programs; boldface can also be indicated in hypertext markup.
boldface font
A font which has specially styled characters that are darker and heavier than normal type, instead of a regular text font that has been made bold.
Bolt, Beranek and Newman, Inc.
(BBN). A Cambridge, Massachusetts, company which was awarded the original contract to build ARPANET and subsequently has been involved in many aspects of Internet development.
bomb
1. To crash; usually referring to software or system failure. On the Macintosh and Atari ST, a system failure is graphically illustrated with a little bomb icon. 2. Code that is hidden in a program or system, either maliciously or as a prank, which will cause something to happen later on. See logic bomb, time bomb.
Bonnie
An open systems benchmark program that can be run under various versions of UNIX, Solaris, and Linux.
bookmark
A feature of Gopher and most Webbrowsers. Important links can be saved in a bookmark file so they can be found immediately without having to look up the URL and type it in.
bookmarks
1. Paper or ribbon markers put in a book to mark the page. 2. A feature of Gopher and most Webbrowsers. Important links can be saved in the bookmarks file so they can be found immediately without having to look up the URL and type it in.
Boole, George
(1815-1864) The mathematician who represented logical reasoning with mathematical formulas; inventor of Boolean algebra. Modern digital computing is based on Boole's work.
Boolean
Having two possible values (such as 0 or 1, on or off, true or false). Referring to a system of algebra and logic developed by English mathematician George Boole.
Boolean algebra
A system of mathematics developed by George Boole in the 1850s. Boolean algebra uses the operators AND, OR, and NOT; operations are carried out on variables which can have one of two values: 1 (true) and 0 (false). Combinations of AND, OR, and NOT are used to construct the additional functions of XOR, NAND, and NOR. Boolean algebra is very important in computers.
Boolean data
Data that can have the value of 1 or 0; these values are also represented as yes or no, on or off, true or false.
Boolean logic
Logic derived from Boolean algebra. Boolean logic is the basis of modern digital computing, in which the opening and closing of electronic switches represent the truth values 1 (true) and 0 (false) and the functions AND, OR, and NOT.
A query using one or more of the Boolean operators AND, OR, and NOT. For example, a search for all species of snakes which live in North America OR South America, do NOT live in Africa, AND are poisonous. See Boolean algebra.
boot
1. To load a computer’s operating system. 2. The process of loading a computer’s operating system.
BOOTstrap Protocol. A TCP/IPprotocol used to enable a diskless workstation to find its own logical IP address at startup.
bootpc
The bootp client for Linux. It allows a Linux machine to retrieve its networking information from a server, over the network. First bootpc sends out a general broadcast asking for the information; then the server sends the information back.
bootstrap
To load and start the operating system on a computer. It comes from the expression “to pull oneself up by one’s bootstraps,” and is often abbreviated as “boot.”
A Scotts Valley, California software company which is known for Turbo Pascal, Turbo C, Turbo Prolog, and Borland C++. Borland acquired the dBASEdatabase software from Ashton-Tate in 1991. The Borland Database Engine enables remote database access across multiple platforms for Windows machines.
bot
Short for robot. A computer program that performs a function such as forwarding e-mail, responding to newsgroup messages, or searching for information.
BOT
Beginning Of Tape.
bounce message
A message indicating an electronic mail message was not delivered, either because it was misaddressed or a connection failed.
bounced e-mail
An electronic mail message returned with a notice indicating the transmission failed, either because the message was misaddressed or a connection failed.
Bourne shell
(sh). An early command interpreter and script language for UNIX, by S.R. Bourne of Bell Laboratories.
BOV
Beginning Of Volume.
bpi
Bits Per Inch. A measurement of the recording density of a tape or disk.
Business Process Re-engineering. To make radical changes in an organization from the ground up in an aim to improve performance and make more efficient use of resources. The concept of BPR generally includes the use of computers and information technology to organize data, project trends, etc.
bps
Bits per second. The rate of data transfer over a communication line. The data rate of a modem is measured in kilobits per second.
1. ASCII characters 123 and 125: { and } . 2. Symbols that are used by computer programmers to mark the beginning and end of a contained area.
brackets
ASCII characters 91 and 93: [ and ] ; left bracket and right bracket.
brain-controlled computer
A computer that can be interfaced with the human brain. One example is a computer system that has been developed to enable totally immobile and speechless people to communicate. A device is implanted into the subject which reads neural impulses from the brain and translates the impulses to the movement of a pointer on the screen. For example, thinking of the left foot causes the mouse to move to the bottom left of the screen.
break key
A key on some keyboards that interrupts whatever process is running. The BREAK key can also be used to restart when the computer freezes or bombs.
Breakout Box
(BoB). A testing device for multiple line cables that makes a connection to each line to see if a signal is present.
BREW
Binary Runtime Environment for Wireless: Qualcomm’s open source application development platform for wireless devices equipped for CDMA technology. BREW makes it possible to create applications that will work on any CDMA handsets.
BRI
Basic Rate Interface. Basic ISDN service at 128 kbps.
brick and mortar
Refers to an organization that has a physical site, rather than a virtual organization.
bridge
A device that governs the flow of traffic between networks or network segments and forwards packets between them. The bridge *ows a message across if it is addressed to the other side; messages within the network are kept within the network, thus making the flow of traffic more efficient.
brightness
The amount of light coming out of the display screen, adjustable with a button or knob on the front of the computer, or by a control panel.
British Naval Connector
(BNC). A plug and socket connector used most often with coaxialEthernet cable. The connector is first inserted into the socket, then turned to lock tight by means of a bayonet mechansim . See also BNC .
broadband
A transmission medium that can carry signals from multiple independent networkcarriers on a single coaxial or fiber optic cable, by establishing different bandwidth channels. This technique is called frequency-division multiplexing. Broadband technology can support a wide range of frequencies and is used to transmit data, voice, and video over long distances. Contrast with baseband.
broadband integrated services digital ne
(B-ISDN). A high-speed telecommunications service which can transmit multimedia over the phone line. It uses fiber optic cable and synchronous transfer mode, and is faster than narrowbandISDN. B-ISDN can be used for voice, data, fax, e-mail, full motion video, and video conferencing.
broadcast
A transmission sent to many unspecified receivers at a time by means of a computer network, radio waves, or satellite. Broadcasting differs from multicasting and narrowcasting, in which a transmission is sent to a group of selected receivers. A broadcast is sent to everyone who has the equipment to receive it. On an Ethernet, a broadcast packet is one which is transmitted to all hosts on the network.
broadcast address
A central address which will forward any messages sent to it to all user addresses on a network.
Broadcast Hypertext Markup Language
(BHTML). A markup language based on XML, designed for synchronization of digital television, data, and Internet technologies.
broadcast packet
A packet which is transmitted to all hosts on an Ethernet.
broadcast storm
A chain reaction that can be caused when an incorrect packet broadcast on a network forces many hosts to respond all at once, shutting down the network. This can happen for various reasons, from hardware malfunction to configuration errors and bandwidth saturation. Broadcast storms can be minimized by properly designing the network.
broadcasting
Sending a transmission to many unspecified receivers at a time by means of a computer network, radio waves, or satellite. Broadcasting differs from multicasting and narrowcasting, in which a transmission is sent to a group of selected receivers.
brochureware
A product that is advertised, but not yet available.
Brooks' Law
The more people you add to a late software project, the later it gets. Dr. Fred Brooks was project manager for IBM's OS/360 operating system in the 1960s, which turned out to be the largest, most complex, and riskiest software project ever undertaken by IBM. The lessons Brooks learned from the project were published in 1975 and later updated in The Mythical Man-Month: 20th Anniversary Edition (Addison-Wesley, 1995).
brouter
1. A combination bridge and router. 2. A device which performs bridging or routing functions, depending on which one is needed for the transmission.
brownout
A temporary drop in electric power without the power going completely off. A brownout may make the computer screen flicker, and can cause loss of data that has been entered but not saved yet.
browse
To view, or to look over casually searching for something of interest.
To make web surfing faster, web browsers store recently visited pages on the user's disk. When the site is revisited, the browser displays pages from the cache instead of requesting them from the server. Reloading will bring up the current page from the server.
BrowserComp
A benchmark that tests browsers for their ability to use forms, audio and video, frames, Java, and other up-to-date World Wide Web technology.
BSA
Business Software Alliance. An alliance of software publishers created to fight software piracy in countries around the world, by educating the public and getting laws passed.
BSD
Berkeley Software Distribution (or Berkeley Standard Distribution or Berkeley System Distribution). Refers to UNIXsoftware and networking products developed at the University of California at Berkeley.
Berkeley Software Design, Inc. The company responsible for BSD/OS, a commercial operating system based on BSDUNIX (technology from the University of California at Berkeley).
A reserved area of memory for temporarily holding data. A buffer can hold data being sent from a high-speed device to a low-speed device until the slower device can accept the input; for example, to hold data sent to a printer until the printer is ready for it.
buffer overflow
A condition that happens when a buffer tries to store more data than it can hold. The buffer should stop accepting data when it is full.
bug
An error in a computer program or in the computer's hardware that causes repeated malfunctions.
bullet
A large dot • used as a design element in text; often used to set off each item in a list. This kind of list is called a bulleted list. Example: • Item 1 • Item 2 • Item 3
bulletin board system
(BBS). A computerized version of the bulletin boards found in stores and other public places, where people can leave messages and advertise things they want to buy or sell. BBSs are often run by local computer user groups, and offer downloads of shareware and freeware plus online information and services. There are special interest bulletin boards, including those run by computer companies to provide information on their products. Many BBSs now have Web pages.
BulletProof
An FTP program that is designed to protect data transmissions when the connection is broken. After a broken connection, BulletProof FTP automatically reconnects and resumes the transmission from where it stopped.
bundled software
Software that comes free with the purchase of new hardware, usually a variety of basic programs and sometimes an encyclopedia, sample computer games, or other multimedia software.
Bundy Manufacturing
A Poughkeepsie, New York time-clock company that merged with other companies in 1911 to form the Computing-Tabulating-Recording Company, which in 1924 was renamed the International Business Machines Company (IBM).
burn
To write data onto a write-once medium such as a recordable CD-ROM.
burn-in period
A factory test of a new electronic system, designed to catch any obvious problems before the computer gets to the customer. The system is run for a length of time to check for weak components, which often fail within the first few hours the computer is run.
Burroughs
A company responsible for many milestones in computing. In 1886 the American Arithmometer Company was founded to manufacture and sell first commercially viable adding and listing machine, invented by William Seward Burroughs. It was renamed the Burroughs Adding Machine Company in 1905. In 1911 it introduced the first adding and subtracting machine. In 1923 Burroughs came out with a direct multiplication billing machine. In 1925 the first portable adding machine, weighing 20 pounds, made machine computation more popular. A million machines had been shipped by 1928. Burroughs pioneered the first 10-key adding machine in 1953, and magnetic ink character recognition in 1959. In 1961 the Burroughs B5000 Series was the first dual-processor and virtual memory computer. The A Series, forerunner of the ClearPath HMP NX system, appeared in 1981. In 1986 Burroughs merged with Sperry to form Unisys Corporation.
bus
A set of conductors which connect the functional units in a computer. It is called a bus because it travels to all destinations. There are local busses that connect elements within the CPU and busses which connect the computer to external memory and peripherals. The bus width determines the speed of data transmission. Most personal computers use 32-bit busses both internally and externally. Internal busses are configured in parallel; there are also serial busses between computers in networks.
A machine that facilitates filing, word processing, accounting, or other office work. Typewriters, adding machines, cash registers, and computers are all business machines. IBM means International Business Machines.
business process re-engineering
(BPR ). To make radical changes in an organization from the ground up in an aim to improve performance and make more efficient use of resources. The concept of BPR generally includes the use of computers and information technology to organize data, project trends, etc.
(BSA). An alliance of software publishers created to fight software piracy in countries around the world, by educating the public and getting laws passed.
busses
Conductors which connect the functional units in a computer. See bus.
button
A little clickable box on the computer screen that is a shortcut for a command. A button may have an icon that indicates what it does; for example, a picture of a fax machine which can be clicked on to activate fax software.
button bar
A horizontal strip of buttons across the top of a window which can be clicked instead of entering the equivalent keyboard commands. Some applications allow the user to custom program some of the buttons, and choose whether to hide or display the button bar.
Byron, Ada
Augusta Ada Byron (1815- 1852), daughter of Lord Byron. She was a mathematician and worked with Charles Babbage. The programming language Ada is named after her.
byte
The amount of memory space used to store one character, which is usually 8 bits. A computer that has 8-bit bytes (most large and small computers today) can distinguish 28 = 256 different characters. See bits, kilobytes and megabytes.
(BIX). An online computing database from Byte magazine, providing technical support for computer users and information on hardware and software products.
byte-oriented protocol
A communications protocol in which the control codes are full bytes rather than single bits.
C
A high-level programming language designed by Dennis Ritchie at AT&TBell Labs, in the 1970s. C was developed to allow UNIX to run on a variety of computers. C is becoming popular as an alternative to assembly language for some uses, and can be compiled into machine language for almost all computers.
Client/server. A method of networking in which a client machine sends a request to a server machine, which provides files, database searches, and other services.
C&P
Cut and Paste. Deleting a block of material (text or graphics, or both) from one place and moving it to another place. The expression is taken from production room layout, where originally cutting and pasting was done by hand.
C#
Pronounced “c sharp.” A new programming language from Microsoft, it was created so that programmers can make a variety of applications – from system level applications to high level business objects – for Microsoft’s .NET platform. Microsoft sees C# as a way to overcome productivity issues it sees as coming from languages such as C and C++.
C++
An object-oriented version of C created by Bjarne Stroustrup at AT&TBell Laboratories in 1986. In C, “C++” means “add 1 to C.” C++ is the basis of the Java language.
C2
Command and Control. This is a military term. Command and control systems are management information systems that help monitor and control operations; for example, the computer systems that control nuclear weapons.
CA
Compression Active. A modem status signal indicated by a light on the modem, which means that the data sent will be compressed.
cable
A flexible wire or bundle of wires, usually metal (glass or silica in fiber-optic cable), insulated with plastic or rubber, and having connectors on the ends. Some kinds of cable, especially coaxial cable and fiber-optics cable, are used in electronics and computer networking.
cable modem
A cable modem is an external device that hooks up to your computer and
instead of getting an internet connection through your telephone wire (or
another system), you get a connection through your cable network (same
place your cable TV connection comes from). Cable modems translate radio
frequency (RF) signals to and from the cable plant into Internet Protocol (IP),
the communications protocol spoken by all computers connected to the
Internet. Cable modems are designed to take advantage of the broadband
cable infrastructure enabling peak connection speeds over 100 times faster
than traditional dial-up connections.
cache
a storage device that is high-speed and can be used as either a main memory or as an independent high-speed storage device.
cache
A temporary storage area for frequently-accessed or recently-accessed data. Having certain data stored in cache speeds up the operation of the computer. There are two kinds of cache: internal (or memory cache) and external (or disk cache). Internal cache is built into the CPU, and external cache is on the motherboard. When an item is called for, the computer first checks the internal cache, then the external cache, and finally the slower, main storage. A cache hit (accessing data from a cache) takes much less time than retrieving information from the main memory; the cache has high-speed memory chips. The cache may also be used as a temporary storage area for data that will be written to disk when the computer is idle.
cache coherency
The management of a cache so that data is not lost, corrupted, or overwritten.
cache hit
The successful retrieval of requested data from the cache. Since a cache hit is faster than reading information from the main memory, the more cache hits, the faster the computer will operate. The larger the cache, the more chance that a particular file will be in cache.
cache memory
A high-speed buffer storage that is smaller than the main storage. The cache memory temporarily stores instructions and data from the main storage that will likely be used next by the CPU.
cache miss
A failure to find requested data in the cache; this means the slower memory must be searched.
Computer Aided Design. In fields such as engineering and architecture, CAD uses computer graphics to do work that formerly would have been done with pencil and paper. CAD requires a high-resolution monitor and special software.
CAD/CAM
Computer Aided Design/Computer Aided Manufacturing. A combination of CAD and CAM. For example, a designer creates a 3-dimensional representation of an object, with the help of the computer, and then the computer programs instructions for automated manufacture of the object and controls the manufacturing process.
CADD
Computer Aided Design & Drafting. CAD systems with features added for drafting.
caddy
The plastic and metal case that a CD-ROM is put in before inserting it into the CD-ROM drive.
CAE
Computer-Aided Engineering. Using computers to help with engineering design work.
Caesar Cipher
A cipher which replaces each letter of the message by a letter a fixed distance away. This cipher was supposedly used by Julius Caesar.
CAI
Computer Aided Instruction. Using computers as aids for instructional purposes. Some people find computer instruction helpful because it allows them to learn at their own pace.
Cairo
The code name for an object-oriented version of Windows NT.
calculator
A machine that performs arithmetic operations. Numbers and operational commands are entered by means of a keypad. Results of the operations appear in a readout window, or in some calculators can be printed on paper tape. Personal computers have a calculator function.
calendar program
A calendar on the computer. Calendar programs usually have appointment book and a way for the user to enter reminders or "to-dos." Alarms can be set for important items, and the calendar can be programmed to open when the computer is booted, to show what needs to be done that day.
call
A programming statement that temporarily transfers control of execution to a subprogram. When the subprogram ends, the main program resumes.
CALL
Computer Aided Language Learning. The use of computers in learning a language.
CAM
Computer-Aided Manufacturing. The use of computers in manufacturing, including automated manufacture. See also CAD, and CAD/CAM.
camera ready
Ready for printing. A page layout (which may contain type, images, or both) that is ready for printing goes to the camera department where negatives are shot; the negatives are then used to make plates for the printing press. New computer technology is evolving which can bypass the camera and prepress stages, using a digital press to print directly from a computer file.
CAML
Computer Animation Movie Language.
Campus-Wide Information System
(CWIS). Publicly available computer systems provided in kiosks on university campuses where users can access directories, databases, bulletin boards, calendars, and other information services.
cancel
A button in a dialog box that cancels any changes the user may have clicked in the dialog box, and allows the user to exit.
cancelbot
A program that locates all newsgroup messages that originate from a particular person or ISP, and cancels (erases) them. Cancellation of all messages from a given source is a form of punishment for too much spam originating from that source.
A unit used to measure luminous intensity in the International System of Units. One candela is the amount of light intensity generated by one ordinary candle.
CAP
1. Carrierless Amplitude and Phase Modulation. AT&T's modulation technology for ADSL (Asymmetric Digital Subscriber Line). 2. Computer-Aided Planning. Using computers to organize data and plan for production.
capacitor
An electronic component that stores electrical charge. In a computer, capacitors are used in dynamicRAMcells and power supplies.
caps lock
On the computer keyboard, a key which makes all the letters print in capitals when it is in its lock position; it is locked by pressing down and unlocked by pressing again. The number keys on the keyboard are not affected by caps lock.
capture buffer
An area of memory that stores incoming data until the computer can process it.
Carbon
Carbon is a set of programming interfaces that let developers build Mac OS X applications that also run on most Mac OS 8 and 9 systems. It’s designed to provide a gentle migration path for developers transitioning from Mac OS 9 to Mac OS X. Carbon makes it possible to take advantage of advanced Mac OS features while preserving developers’ investment in learning OS 8 and 9 source code.
card punch
A device used to punch holes in stiff paper cards, in patterns that can be read by a computer. The first use of punched cards was in 1801 on the automatic Jacquard loom in France. Punched cards for data processing were developed by Hermann Hollerith to use for the 1890 U.S. Census. Punched cards were used in the 1960s to feed data into computers.
card reader
1. An early device for reading punched cards by the patterns of light shining through holes in the cards. 2. A device that reads the magnetic stripes on credit cards.
caret
^ (ASCII 94), typed by shifting the number 6 key on the keyboard. Sometimes used as a symbol for the control key; for example, ^S = Control-S.
careware
Shareware made available with the request that the user donate something to a particular charity.
carpal tunnel syndrome
Injury of the carpal tunnel, a nerve pathway in the wrist, that is sometimes caused by long hours of typing. The primary symptoms are numbness, tingling, and pain in the fingers caused by pressure on the main nerve to the hand. Stretching exercises, massage therapy, or medication will help mild cases; if the condition is severe, it may require surgery. To prevent carpal tunnel syndrome, typists can use a padded wrist support, take breaks and stretch the hands from time to time.
carriage return
In early typewriters, a carriage return was made by a lever that pushed the carriage to the left to begin a new line. Eventually typewriters refined this lever to a key pressed with the little finger, equivalent to the return key on a computer keyboard that sends the cursor down to begin a new line. Within the computer printer, the equivalent to the carriage return is the mechanism that controls paper feeding and movement of the print head.
carriage return character
ASCII character 13. The carriage return character ends a line or paragraph. See carriage return.
carrier
A continuous electric signal which vibrates at a single frequency, and can be modulated by other signals to carry information, such as computer data, sound, or video. Carrier signals are used in telephony, radio, TV, and satellite communications.
Carrier Sense Multiple Access with Colli
(CSMA/CD). Ethernet packets are transmitted using CSMA/CD, which means the sending computer waits for the line to be free before sending a message; if two computers accidentally transmit at the same time and their messages collide, they wait and send again at different times.
A self-contained, removable module that is inserted into a slot in the computer or printer. Toner or ink cartridges are used in the printer; magnetic tape is protected within a cartridge; and game software in the form of plug-in cartridges is popular. Memory chips can come in cartridges; a font cartridge is one example.
cascade
A way of arranging open windows on the computer screen so that they overlap diagonally with each title bar showing.
cascading style sheets
(CSS). A style sheet mechanism that has been specifically developed for Web page designers and users. Style sheets describe how documents are presented on screens, in print, and even in spoken voice. Style sheets allow the user to change the appearance of hundreds of Web pages by changing just one file. A style sheet is made up of rules that tell a browser how to present a document. Numerous properties may be defined for an element; each property is given a value. Examples are font properties, color and background properties, text properties, box properties, classification properties, and units. The term cascading refers to the fact that more than one style sheet can be used on the same document, with different levels of importance. There are differences between CSS and XSL (Extensible Style Language). Both languages can be used with XML, but only CSS can be used with HTML. XSL, however, is a transformation language, and can be used to transform XML data into HTML/CSS documents on a Web server.
case
1. The property of being capitalized (upper case) or not capitalized (lower case). The uppercase letters on the keyboard are made by pressing the shift key at the same time as the letter, or leaving the caps lock key down. ASCII code has a different designation for an uppercase letter and its lowercase letter. 2. A box that contains the components of a computer system.
CASE
Computer Aided Software Engineering. The automation of some of the methodologies used in software engineering.
CASE Data Interchange Format
(CDIF). A mechanism that makes it possible to move information from one CASE tool to another. Users often work with many different Computer Aided Software and Systems Engineering (CASE) and visual modeling tools, and interoperability is important. CDIF evolved from Extensible Markup Language (XML).
case insensitive
Making no distinction between uppercase and lowercase letters; the opposite of case sensitive. Internet domain names are case insensitive.
case sensitive
Treating upper case letters as different characters from the same letters in lower case. Filenames or text searches which are case sensitive would distinguish between, for example, Internet and internet; this distinction would be useful in some situations and inconvenient in others.
cassette
A module which encloses and protects a length of magnetic tape, which is wound between two reels past an opening through which the tape is read. Cassettes are used to store audiotape, videotape, DAT tape, and other kinds of magnetic tape used for computer storage.
CAST
Computer-Aided Software Testing. The use of an automated program for software testing.
cat
The UNIX command used to display a file's contents; short for concatenate.
CAT
Computer Aided Testing.
catalog
On the computer, a catalog is a directory of files, or a directory of storage space.
catenet
A network made up of different kinds of networks interconnected by routers. The Internet is a catenet.
(CRT) A glass vacuum tube with a fluorescent screen that glows when struck by electrons. Images are displayed by electron beams which constantly scan the screen; a variable electromagnetic field within the tube directs these beams. TV screens and computer monitors both contain cathode ray tubes.
www.cauce.org.
CAV
Constant Angular Velocity. The writing or reading mode used with a hard disk, floppy disk, or laserdisc. The disk rotates at a constant speed, and the number of bits in each track is the same, but because the inner tracks are smaller in circumference than the outer tracks, their density is less. CAV wastes disk space this way compared with constant linear velocity (CLV), but makes data retrieval fast and is a good way to store high-resolution photos or video.
CAVE
(Computer Automatic Virtual Environment). A reality simulation in which the user does not wear goggles, but images are projected on the walls and ceiling giving an illusion of 3-D reality.
CB
Citizens Band. The range of radio wave frequencies allocated for private radio communications.
CBEMA
Computer and Business Equipment Manufacturers Association. A Washington, D.C. organization that develops standards for computers and business equipment worldwide.
CBM
Commodore Business Machines. A pioneering company in the personal computer industry; maker of the PET, Commodore, and Amiga computers. The company went bankrupt in 1994. In 1995 the German company Escom AG bought Commodore Business Machines with the intention of manufacturing Amigas once again.
CBMS
Computer Based Message System.
CBR
Constant Bit Rate. A constant rate of transmission, required for voice transmissions.
CBT
Computer-Based Training. Training through use of a computer.
CBX
Computer-controlled Branch eXchange. A telephone switching system that connects telephone extensions to each other within a company or building. Also called PBX.
Coordinating Committee for Intercontinental Research Networks. A committee made up of major North American and European research organizations, whose goal is international cooperation among research networks. Its membership includes the United States Federal Networking Council (FNC), the European Association of Research Networks (RARE), and other research organizations.
CCITT
Commite Consultatif International de Telegraphique et Telephonique. (International Consultative Committee on Telecommunications and Telegraphy). Now called International Telecommunications Union (ITU), in Geneva, Switzerland. ITU is one of the organizations working on forming international standards for communication. ITU-T is the arm of ITU responsible for telecommunications standards.
CCP
Certificate in Computer Programming. A certificate awarded by the Institute for Certification of Computer Professionals which indicates the bearer has passed an examination, and has some computer education or job experience.
CCR
Commitment, Concurrency, and Recovery. An OSI application service element which is used to create atomic operations over distributed systems. CCR is used to implement two-phase commit for transactions and operations that run nonstop.
ccw
Counterclockwise.
CD
1. Compact Disc. A format for storing audio data in digital form, which can be played on a CD player or with a CD-ROM drive. 2. Carrier Detect. A modem status signal indicated by a light on the modem. Carrier detect means a carrier frequency has been detected on the line, indicating a successful connection has been made.
Various formats of compact discs have been derived from the original audio CD. Specifications for these CD formats are listed in a series of books named after the color of their covers. The Red Book describes audio CDs, also called compact disc-digital audio (CD-DA). The Yellow Book describes the compact disc-read only memory (CD-ROM) format. The Orange Book is for write-once CDs (CD-WO), as the photo CD and compact disc-recordable (CD-R). The Green Book describes compact disc-interactive (CD-I), and the White Book is for video CDs (CD-V).
CD ripper
A program that enables the user to digitally copy songs off a CD into many different formats including WAV, AIFC, and more.
CD-Bridge disc
A CD-ROM XA disc that can be played with a CD-ROM XA player or a CD-I player, allowing the output to be displayed on either a computer or TV screen.
CD-DA
Compact Disk – Digital Audio. An audio CD. A 4.72″-diameter disc containing digital audio information, originally developed by Phillips and Sony as a format for very high-fidelity sound. The disc can contain up to 72 minutes of sound. A compact disc is recorded on one side only, and tracks can be played in any sequence. To make the CD, sound waves are sampled 44,056 times per second and converted into digital format, then recorded as microscopic pits which are read by a laser-equipped player. CDs and CD-ROMs are made using the same technology; both have a spiral recording track like a vinyl record, and use constant linear velocity. CDs quickly became popular because of the high quality of digital sound. Audio CDs can be read by special audio CD players, or by CD-ROM players.
CD-E
CD-Erasable. An erasable CD, which requires a special CD-E drive. The CD-E drive can read and write CD-E disks, CD-R disks and CD-ROM disks.
CD-I
(Compact Disc-Interactive). An optical disc that is physically the same as an audio CD, but contains multimedia information (images, sound, etc.) The user can interact with films, games and educational programs. CD-I discs require a CD-I player, which can be used as an accessory to a TV set, and will not play in a standard CD-ROM player.
CD-M
Also called CD-MIDI. Compact Disc-Musical Instrument Digital Interface. A CD system on a computer that enables the user to work with MIDI instructions for electronic instruments, including reading musical scores and editing. CD-MIDI can display visual information that corresponds with the sounds as they are played.
CD-MIDI
Also called CD-M. Compact Disc-Musical Instrument Digital Interface. A CD system on a computer that enables the user to work with MIDI instructions for electronic instruments, including reading musical scores and editing. CD-MIDI can display visual information that corresponds with the sounds as they are played.
CD-R
Compact Disc Recordable. A recordable CD-ROM which can be read by normal CD-ROM drives; data can only be recorded once onto a CD-R, and cannot be changed.
CD-RDx
CD-ROM Read Only Data Exchange. A CD-ROM standard developed by the CIA for ISO-9660-compatible computers, used for read-only data.
CD-ROM
Compact Disc Read-Only Memory. An optical disc that is physically the same as an audio CD, but contains computer data. Storage capacity is about 680 megabytes. CD-ROMs are interchangeable between different types of computers.
CD-ROM drive
A disk drive that reads CD-ROMs and audio CDs. It may be installed in the computer or removable. Recordable CD-ROM drives can also record onto the CDs.
CD-ROM drive
A drive that reads CD-ROMs and audio CDs. It may be installed in the computer or removable. Recordable CD-ROM drives can also record.
CD-ROM Extended Architecture
(CD-ROM XA). A CD-ROM format that has audio and graphics, plus extended storage capabilities. CD-ROM XA is used for photo CDs, which store and display high-quality photos in digital format.
CD-ROM extensions
Extensions to an operating system that enable it to read CD-ROMs. MS-DOS has MSCDEX.EXE; Macintosh has High Sierra File Access, Foreign File Access, ISO 9660 File Access, for example.
CD-ROM jukebox
A machine similar to a record or CD jukebox, except that it can read CD-ROMs. It can store a number of CD-ROMs, but only plays one at a time, and has a mechanism for switching from one to another.
CD-ROM Read Only Data Exchange
(CD-RDx). A CD-ROM standard developed by the CIA for ISO-9660-compatible computers, used for read-only data.
CD-ROM tower
A tall box which contains a number of CD-ROM drives. The CD-ROM tower is useful for networks, because all of the drives are accessible at all times.
CD-ROM XA
CD-ROM Extended Architecture. A CD-ROM format that has audio and graphics, plus extended storage capabilities. CD-ROM XA is used for photo CDs, which store and display high-quality photos in digital format.
CD-RTOS
Compact Disc – Real Time Operating System.
CD-RW
CD-ReWritable. A CD-ROM that can be written, erased, and rewritten by the user. CD-RW discs usually will only play on Multi-Read CD-ROM drives; some CD players with exceptional speed may have the sensitivity to read CD-RW discs.
CD-RW drive
CD-ReWritable drive. A CD-ROM drive that can write, erase, and rewrite to a CD-ROM. CD-RW is considered by many to be the perfect bridge from CD to DVD technology because of its backward and forward compatibility with existing CD and future DVD platforms.
CD-Single
An 8-cm. music disc which can store up to 200 K, and can be played by the Sony Data Discman.
CD-V
Compact Disc – Video. An audio CD that can provide up to five minutes of video with digital sound. They can be played in most laser disc players.
Communications Decency Act. An amendment to the U.S. 1996 Telecommunications Act that went into effect in February 1996. The law was intended to protect children from obscenity on the Internet, but many Internet users argued that its language was too vague and that it violated the right of free speech. Protesters against the law turned their Web pages black and displayed blue ribbon icons downloaded from the Electronic Frontier Foundation. In June 1996, a three-judge panel ruled the act unconstitutional. The Justice Department appealed the decision to the U.S. Supreme Court.
CDC
1. An operating system and family of computers from Control Data Corporation including workstations, mainframes, and supercomputers. (Control Data Corporation is now called Control Data Systems). 2. Century Date Change. Another expression for the Y2K date change.
(Compact Disc Data Base). A public database that has information about CDs; for example, song title, track, and artist information. If your player supports CDDB connections, you can record a CD and then have the tracks titled from the database.
CDDI
Copper-Distributed Data Interface. A token-ringnetwork similar to FDDI, but it uses copper cable, and is limited to distances of 50 to 100 meters.
CD-ROM File System. 1. The program for reading CD-ROMs in 5839″>Windows 95. 2. The program Commodore PCs use for reading CD-ROMs.
CDIF
(CASE Data Interchange Format). A mechanism that makes it possible to move information from one CASE tool to another. Users often work with many different Computer Aided Software and Systems Engineering (CASE) and visual modeling tools, and interoperability is important. CDIF is an evolution of eXtensible Markup Language (XML).
CDMA
Code Division Multiple Access. A technique of multiplexing, also called spread spectrum, in which analog signals are converted into digital form for transmission. For each communication channel, the signals are encoded in a sequence known to the transmitter and the receiver for that channel.
CDMA2000
Based on CDMA, this is a 3G wireless technolgy that sports up to twice the voice capacity and data speed on a single 1.25MHz carrier in a new or existing spectrum.
CDParanoia
CD ripper software that reads digital audio directly from a CD, then writes the data to a file or pipe in WAV, AIFC or raw 16 bit linear PCM format. CDParanoia can read data from a variety of hardware devices and can also read and repair data from damaged CDs.
CDPD
Cellular Digital Packet Data. A data transmission technology used to send data to and from cellular devices. CDPD uses cellular channels in the 800-900 MHz range and transmits data in packets. CDPD can achieve data transfer rates up to 19.2 Kbps.
CDR burner
A program for writing to a recordable CD or CD-ROM.
CDTV
Commodore Dynamic Total Vision. CD-ROM multimedia for Commodore PCs, which can be displayed by a TV monitor. The technology is also used for video games and audio.
Celeron
A brand of processors from Intel for the basic PC market, available in 333-MHz, 300A-MHz, 300-MHz and 266-MHz operating frequencies. All Celeron processors are based on the Intel 0.25 micron CMOS process technology. The processors are in the single edge processor package (SEPP). They have the same P6 microarchitecture core as the Pentium II processor, and provide the performance to run most common applications on operating systems. They are designed for dependability and cost efficiency.
cell
A box in a spreadsheet or table where data can be entered.
cell address
Exact designation of a cell's location in a spreadsheet, indicated by a column letter and a row number. The address D4 would be in column D, row 4. Also called cell reference.
cell reference
Exact designation of a cell's location in a spreadsheet, indicated by a column letter and a row number. The address D4 would be in column D, row 4. Also called cell address.
cell relay
A packet-switching technology that divides a transmission into small fixed-length cells, sends them over the network, then puts the complete message back together at the receiving end. In the X.25 and frame relay packet-switching methods, the packets vary in length; having small uniform-sized packets (cells) makes it possible to send information faster. Asynchronous transfer mode makes use of cell relay technology.
CellPhimportance is a condition in which ones cell phone takes all precedence over everyone or everything in it’s surrounding area.
His CellPhimportance has earned the him the reputation of just being rude.
cellular phone
A type of wireless mobile telephone service in which a service area is divided into multiple cells, each served by a base station. Calls are transferred from base station to base station as the user travels from cell to cell. Cellular service uses the 800 MHz frequency band.
center tab
A tab in which the text is centered around the tab stop.
centering
Aligning text around the center of a page; usually refers to horizontal alignment.
centillion
10^303 (U.S. and Canada); 10^600 (Europe).
centimeter
(cm). A unit of measurement; 1/100th of a meter or (0.39 inch).
central processing unit
(CPU). The central processing unit controls the operation of a computer. Units within the CPU perform arithmetic and logical operations and decode and execute instructions. In microcomputers, the entire CPU is on a single chip.
Centrino
Intels pentium chip version of mobile technology, which includes wireless networking, and increased battery life
Century Date Change
(CDC). Another expression for the Y2K date change.
Cerf, Vincent
President of the Internet Society (ISOC) and cocreator of TC/IP with Bob Kahn.
Conseil Europeen pour la Recherche Nucleaire (European Laboratory for Nuclear Research). A high-energy physics research center in Geneva, Switzerland, where the World Wide Web was developed.
www.cert.org
Certificate in Computer Programming
(CCP). A certificate awarded by the Institute for Certification of Computer Professionals which indicates the bearer has passed an examination, and has some computer education or job experience.
Certified Systems Engineer
(CSE). Certification level from Microsoft for technical specialists in Windows NT and other Microsoft software.
cfm
Like .com and .org, this is a URL extension; it stands for “cold fusion” and is created by the company Allaire Corporation. Similar to Microsoft's Visual Interdev yet more popular, .cfm is a format allowing you to link databases and spreadsheets to your webpage much easier than via HTML coding.
CGA
Color Graphics Adapter. An early IBM hardware video display standard, with a maximum resolution of 640×200 pixels. It was widely used in the mid-1980s, but then was superseded by EGA.
CGI
Common Gateway Interface. A way of interfacing computer programs with HTTP or WWW servers, so that a server can offer interactive sites instead of just static text and images.
CGI script
Common Gateway Interface script. A program that is run on a Web server, in response to input from a browser. The CGI script is the link between the server and a program running on the system; for example, a database. CGI scripts are used with interactive forms. See also CGI
cgi-bin
Short for Common Gateway Interface-BINaries. A special directory where common gateway interface (CGI) scripts are kept. Since a CGI program is executable, having a CGI script on a Web page means allowing everyone who visits the page to run a program on the system, which is not very safe. Putting the CGI script in its own directory is a security precaution; the cgi-bin can be under direct control of the webmaster, which prohibits the average user from creating CGI scripts. Putting a script in the CGI bin also lets the Web server know to run the program rather than just display it to the browser.
CGM
Computer Graphics Metafile. An ANSI standard format for exchanging graphics files between applications, in both vector and raster formats.
ch
Top-level newsgroup category for a Swiss newsgroup.
chad
The scrap left when a hole is punched in paper or tape.
chain printer
A kind of impact printer in which the character slugs are moved by the links of a revolving chain.
chained list
A list in which each data element points to the next. The chained list makes it possible to list data elements in sequence although they may be dispersed.
(CHAP). A way of authenticating the identity of a user on a PPP server. CHAP uses a three-way handshaking procedure, and provides more security than PAP. The identity of the user can be challenged at any time while a connection is open. CHAP is described in RFC 1334.
Channel
This is when two devices are linked either externally in internally.
The waiting time for a communications channel to be available to transmit data.
channel op
A user who has powers on an IRC (Internet Relay Chat) channel. The channel op may be responsible for monitoring the channel, and denying privileges to those who misuse it.
chanop
Channel operator, or channel op. A user who has powers on an IRC (Internet Relay Chat) channel. The channel op may be responsible for monitoring the channel, and denying privileges to those who misuse it.
CHAP
Challenge-Handshake Authentication Protocol. A way of authenticating the identity of a user on a PPP server. CHAP uses a three-way handshaking procedure, and provides more security than PAP. The identity of the user can be challenged at any time while a connection is open. CHAP is described in RFC 1334.
char
Abbreviation for character, used in computer programming.
character
A symbol that represents information, or the representation of that symbol by a computer. Letters of the alphabet, numbers, and punctuation symbols are characters; so are some keyboard commands. ASCII, ANSI, and EBCDIC are coding systems for translating each character into one byte to be read by the computer.
character field
A data field for typing in alphanumeric characters.
character format
Instructions for the size (in points), style (bold, italic, small caps, etc.), position (normal, superscript, etc.), spacing (condensed, expanded, etc.), font, and color of typeset characters.
Character Map
An interactive keyboard layout in Windows that shows for each typeface the characters available in uppercase, lowercase, and with option keys. The equivalent utility for Macintosh is Key Caps.
character pitch
The number of characters per inch (cpi) in a typeface or a page of type. In fixed-pitch type, each character takes up the same width; in proportional-pitch type, the i takes up less width than the m, and character pitch is an average number.
character printer
A printer that prints a single character at a time.
character recognition
The ability of a computer to recognize printed characters. For example, when a page of text is scanned using a regular scanning program, the page will be read as a graphic; the computer does not recognize individual characters but only takes a picture of the page. When optical character recognition (OCR) is used, the computer recognizes each individual character and creates a text file out of the scanned page, which can be edited or formatted like any other text file. Magnetic ink character recognition (MICR) is used by banks to read characters on checks and convert them into digital information.
character role playing game
(CRPG; also called RPG). A game which may be played on computer or with pen and paper, in which the players act out a different reality. Classic role-playing games involve creating a character, assigning a set of attributes such as strength, dexterity, willpower, charisma, etc., and moving the character through adventures in a fantasy, historical, or futuristic environment, usually containing enemies to fight and treasures to find. The game is often led by a gamemaster or dungeonmaster who does not play a character but who has keys to the game, hidden rules, and a secret map that the players can't see; the gamemaster tells a player what each room looks like upon entering, when he has run into something invisible, whether he hit the dragon enough times to kill it, etc. The first gamemaster is usually the designer of the game.
A set of characters which may include letters, numeric characters, punctuation marks, symbols, signs, and control codes. ASCII is the most commonly used character set. EBCDIC and Kanji are other well-known character sets. For use in a computer, each character in a set has its own code, a binary number which the computer recognizes.
A computer interface that shows only characters and no graphics on the screen.
character-oriented protocol
A communications protocol in which data are transmitted as whole characters rather than as bits.
charge-coupled device
(CCD). Electronic memory in which metal oxide semiconductors are arranged so the output, or charge, from one semiconductor is the input of the next semiconductor. CCDs can be charged by light or electricity. One use is for storing images in digital cameras, video cameras, and optical scanners.
Charisma
A Windows presentation graphics program from Micrografix.
charityware
Shareware for which the payment asked is sending a donation to a favorite charity.
2. To have a real-time conversation online. See also chat mode.
chat mode
A mode in which users can type messages back and forth to each other, which are transmitted in real time.
chat room
A real-time electronic forum; a virtual room where visitors can meet others and share ideas on a particular subject. There are chat rooms on the Internet, BBSs, and other online services.
check box
In a hypertext document, a small box that looks like the checkbox on a paper form. When the user clicks a check box to select an option, an X appears in the box.
CheckFree
CheckFree is a provider of financial e-commerce.
checksum
A value that accompanies data transferred from one place to another and helps to ensure that the data was transferred correctly. The checksum is computed by adding up the bytes or words of the data block. On the receiving end, the checksum is computed based on the data received and compared with the value that was sent with the data. If the two numbers match, the data is considered correct.
Chemical Markup Language
(CML). An application of XML which makes it possible to incorporate chemical symbols into Web pages as easily as text.
CHI
Computer-Human Interface. The kind of interface between a computer and the user determines how easy the computer is to use.
(CIO). The chief executive officer in charge of information processing.
chief technology officer
(CTO). The executive who directs an organization in matters pertaining to technology.
child file
In a database, a file that is the offspring of a parent file and holds additional information.
child program
A subprogram which is loaded into memory and used by the main program.
Chinook
The world champion, artificially intelligent, checkers program. Chinook is a finely tuned program with a gigantic database of checkers positions, running on a massively parallel computer.
CHIO
Channel Input/Output.
chip
Also called microelectronic or integrated circuit. A microelectronic device comprising many miniature transistors and other electronic components on a single thin rectangle of silicon or sapphire, approximately 1/16″ to 5/8″ on a side, and 1/30″ thick. A chip can contain dozens, hundreds, or millions of electronic components. To make a chip, impurities are added to the supporting material, or substrate, in specific places to create P-type and N-type regions; then by projecting light onto light-sensitive chemicals, polysilicon or aluminium tracks are etched into the top 1/1000″ of the substrate to make the electronic circuits. Chips come in analog, digital and hybrid types. Compared with earlier technology, microelectronics are faster, more compact, more energy-efficient, and cheaper to manufacture. The most complete integrated circuit is a microprocessor, a computer on a single chip.
chipset
A group of integrated circuits that are designed to work together for some specific function.
A Macintosh desk accessory that allows the user to select which connected printer or modem to use, and to connect or disconnect from a network.
chop
Channel operator. A user who has powers on an IRC (Internet Relay Chat) channel. The channel op may be responsible for monitoring the channel, and denying privileges to those who misuse it.
Christian Classics Ethereal Library
(CCEL). An experimental theological library on the Internet.
Chromeffects
Add-on technology to Windows 98 that uses eXtensible Markup Language (XML) tags to describe ads or 3-D graphics, or to indicate to the client computer how to create animation locally, rather than sending all the information over the Internet. This technology can help speed up multimedia content transmitted over the Internet.
CHRP
Common Hardware Reference Platform. An open system standard for PowerPCs, later renamed PowerPC Reference Platform. It allows PowerPC-based computers to run different operating systems, including Mac OS, Workplace OS, AIX, OS/2, Solaris, Taligent, and Windows NT. It designates ports and sockets for compatibility across platforms, and can be used with various buses.
Church, Alonzo
A 20th-century mathematician who invented lambda-calculus and was one of the pioneers of computer science.
CIAC
Computer Incident Advisory Capability. This group assists the Department of Energy in its information protection efforts by providing computer security incident response services.
CICS/VS
Customer Information Control System for Virtual Storage (IBM).
CIDR
Classless Inter-Domain Routing. A method for more efficient use of the existing 32-bit Internet Address Space.
CIE
Commission Internationale de l'Eclairage. An international committee for the establishment of color standards. The CIE model and the CIE Chromaticity Diagram define the different variations of color.
CIE Chromaticity Diagram
(Commission Internationale de l'Eclairage Chromaticity Diagram). A two-dimensional drawing of the CIE model, which defines the different gradations of colors in terms of values of lightness, red-green and yellow-blue.
CIE model
(Commission Internationale de l'Eclairage model). A model created by Commission Internationale de l'Eclairage in 1931, showing all possible colors represented in a three-dimensional color space.
cine orientation
A placement of images so they are aligned on the sides and the bottom of an image is connected to the top of the one below it, like the frames in a film strip. See comic-strip orientation.
CIO
chief information officer. The chief executive officer in charge of information processing.
cipher
1. To compute arithmetically. 2. To put into code or secret writing, using substitution of characters or symbols or rules for changing their order. 3. An algorithm for putting a message into code by transposition and/or substitution of symbols.
A type of cryptanalysis in which only the encoded message is available; from this the analyzer must determine the plaintext.
CIR
Committed Information Rate. The minimum transmission speed between computers in a frame relay network.
CIRC
Cross-Interleaved Reed-Solomon Code. A technology used in compact discs for error detection and correction.
circuit
1. The complete path of an electric current including the source of electricity and the conductors through which it flows. 2. A two-way communications path between computers.
circuit analyzer
1. A device for testing an electronic circuit. 2. A device for testing a communications circuit.
circuit board
The flat board in a computer that holds integrated circuits and other electronic components.
circuit breaker
A switch that automatically interrupts an electrical circuit when there is an overload of current or other abnormal condition.
circuit switching
A communications method which establishes a dedicated channel for the duration of the transmission, allowing data to be transmitted in real time. The telephone network is a circuit-switched network.
circular reference
A mistake in a spreadsheet in which a cell contains a reference to itself. For example, cell B4 might contain the formula B3+B4 (which means the value of cell B4 = B3+B4). The computer, confronted with an unsolvable problem, will have to stop and display a warning message.
circularity
A condition in which the computer cannot complete a computation because the computation is unsolvable. For example, in a spreadsheet, cell B4 might contain the formula B3+B4 (which means the value of cell B4 = B3+B4). Since you are ordering the formula to do something to itself, the computer will stop and display a warning message.
A San Jose, California company which manufactures hardware for Ethernets, and other products.
CIT
Computer Integrated Telephony.
city-named fonts
Fonts named after cities, such as Chicago, New York, Geneva, Monaco, Cairo, are usually bitmapped fonts and therefore not scalable. This is why they have ragged outlines when printed. The TrueType versions of these fonts, however, are an exception.
CIX
1. Compulink Information eXchange. 2. Commercial Internet Exchange. A connection point between commercial Internet service providers. Pronounced kix.
CKML
Conceptual Knowledge Markup Language. An application of Extensible Markup Language (XML) which extends the capabilities of Ontology Markup Language (OML). These markup languages enable authors to annotate World Wide Web documents with machine-readable knowledge, thus improving the ability of intelligent agents to gather information.
CL
Control Language. A language by which a user gives commands to a computer to perform certain tasks. It is more limited than a programming language.
CLA
Communication Line Adapter. A device that converts a digital signal into analog form to send it over a communications line, and converts incoming analog signals back into digital. It also converts a serial transmission to parallel to transmit, and converts incoming parallel signals back to serial form.
cladding
The special material used to line or cover an optical fiber; a plastic or glass sheath that surrounds the core of the fiber and is fused to it. The cladding reflects and keeps the light waves to the core and strengthens the fiber.
clamshell
The common design of portable computers, which are hinged and open like a clam shell. Inside the keyboard is on the bottom and the screen is on the top.
clan
A kind of online club, often found in chat areas, graphical chat rooms, or RPGs.
clari
Top-level newsgroup category for a Clarinet news newsgroup.
Claris
Claris Corporation, in Santa Clara, CA, U.S.A. The software company which created ClarisWorks and other programs.
ClarisWorks
A software package for Macintosh and Windows from Claris which includes word processing, spreadsheet, database, drawing, and communications.
class
In object-oriented programming, an object type; a group of objects that have the same properties, operations, and behavior.
classless inter-domain routing
(CIDR). A method for more efficient use of the existing 32-bit Internet Address Space.
clean boot
Starting the computer and only loading the main part of the operating system.
clear
A command that erases information from a spreadsheet, clears the memory in a calculator, or performs similar functions in other programs.
clear memory
To reset memory to zero by restarting a computer or turning it off and on again.
clear to send
(CTS or CS). A modem status signal which means the modem is ready to accept data from the local computer, which it will then transmit to a remote computer.
CLEC
Competitive Local Exchange Carrier. A company or organization providing local telephone services at a reduced cost in competition with a traditional telephone company. CLECs, sanctioned by the Telecommunications Act of 1996, are often established telecommunications service organizations, although any large company, city government or university has the option of becoming a CLEC provided they have a telephone switch, comply with state regulations and fees and open their services to outside customers. Compare with ILEC.
CLI
Call Level Interface. Database programming interface from SQL Access Group.
click
To press a button on a mouse or other pointer. Clicking is used to place the cursor, when working in text, or to select an object on the screen or a menu option.
click and drag
To use a mouse or other pointing device to grab an item on the computer screen and move it to another location. To click and drag, point to an item, click the pointer and hold the button down while dragging the item to the desired location; then release the button.
click art
Click art is clip art on the computer: A collection of non-copyrighted pictures which can be used to illustrate desktop publishing documents.
click rate
The percentage of ad views that result in a user clicking on the ad.
click-through
The percentage of ad views that result in a user clicking on an ad.
clickable
Responding to clicks of the mouse or pointer; for example, hyperlinks open new data areas when they are clicked.
clickable image
An image that, when clicked on, sends some instruction to the computer. Clickable images on World Wide Web pages are linked to URLs; an image that has different areas linked to different URLs is an image map.
clickable image map
A map or other graphic that has “hot spots” or hyperlinks. A user can click on a spot on the map or graphic and link to more detailed information.
client
The computer in a client/server architecture that requests files or services. The computer that provides services is called the server. The client may request file transfer, remote logins, printing, or other available services. The client also means the software that makes the connection possible.
A technology from Apple Computer which makes it possible for a user with a portable computer to access both a server on a network, and the user's own client desktop computer.
client-side image map
An image map in which the map that relates parts of the image to different URLs is stored in the current file.
client/server
An architecture in which one computer can get information from another. The client is the computer that asks for access to data, software, or services. The server, which can be anything from a personal computer to a mainframe, supplies the requested data or services for the client.
client/server network
A network in which one or more computers are servers, and the others are clients, as opposed to a peer-to-peer network, in which any node can be a client and server.
clip art
A set of non-copyrighted images on paper which can be clipped to illustrate brochures, flyers, posters, etc. The computerized version of clip art is called “click art.”
clipboard
An area of temporary memory which is used to transfer text or graphics (or both) within a document being edited, or between documents. The data is put into the clipboard with either the Cut or Copy command, then Paste is used to put it into its new location.
Clipper chip
A microchip originally designed to encrypt telephone messages, later proposed for encoding of data transmissions also. The U.S. National Security Agency wanted to establish the Clipper chip as a national standard, with the federal government holding a master code so it could unscramble transmissions when investigating criminal activity. After much debate, and protests from groups like the American Civil Liberties Union and the Electronic Frontier Foundation, the idea of a single encryption standard was abandoned, but the government placed restrictions on the export of encryption software.
CLK
Clock. 1. A circuit in a computer that uses a quartz crystal to generate a series of regular pulses which are sent to the CPU. The clock is the heartbeat of the computer. Switching operations in the computer take place while the clock is sending a pulse. The faster the clock speed, the more instructions per second the computer can execute. See also clock speed. 2. A circuit within a computer that keeps track of the date and time, normally powered by a battery so it keeps running when the computer is off.
CLNP
Connectionless Network Protocol. The OSI protocol for OSI Connectionless Network Service. CLNP is the OSI equivalent to the Internet Protocol (IP), and has been called ISO IP.
clock
(CLK). 1. A circuit in a computer that uses a quartz crystal to generate a series of regular pulses which are sent to the CPU. The clock is the heartbeat of the computer. Switching operations in the computer take place while the clock is sending a pulse. The faster the clock speed, the more instructions per second the computer can execute. See also clock speed. 2. A circuit within a computer that keeps track of the date and time, normally powered by a battery so it keeps running when the computer is off.
clock rate
The speed at which a computer performs basic operations, usually given in MegaHertz (millions of cycles per second). The clock rate of a computer is determined by the frequency of vibration of a quartz crystal which sends pulses to the CPU. Clock rate can be misleading when used to compare the performance of different types of computers; benchmarks try to take other variables into account.
clock speed
The speed at which a computer performs basic operations, usually given in MegaHertz (millions of cycles per second). The clock speed of a computer is determined by the frequency of vibration of a quartz crystal which sends pulses to the CPU. The clock speed of a computer is determined by the frequency of vibration of a quartz crystal which sends pulses to the CPU. Clock speed can be misleading when used to compare the performance of different types of computers; benchmarks try to take other variables into account.
clock/calendar
A circuit within a computer that keeps track of the date and time, normally powered by a battery so it keeps running when the computer is off.
ClockTools
An application program from the Bloom! Software Group.
clone
A computer that imitates a brand name computer on the market, but is usually sold for a lower price.
CLOS
Common Lisp Object System.
close
To shut a window or file on the computer screen.
clover key
The Macintosh command key, which has a clover shape on it.
CLS
Clear Screen. A command that makes the CRT screen go blank.
CLTP
Connectionless Transport Protocol. A type of interconnection in which communication takes place without first establishing a connection.
The OSI equivalent of UDP.
cluster
A group of sectors on a disk which is treated as a unit.
cluster control unit
A device that manages the input and output of several devices. For example, a cluster control unit may control several disk drives connected to a main computer.
cluster controller
A device that manages the input and output of several devices. For example, a cluster controller may control several terminals connected to a main computer.
CLUT
Color Lookup Table. A table that contains color mixing information, used especially by graphic designers and printers. A formula indicates a color mix by the intensity of red, green and blue in the color. The table can be on paper or in a computer file.
CLV
Constant Linear Velocity. A way of reading and writing data used by CD-ROMs and CDs. Instead of having several tracks arranged in concentric circles, data is contained in a single track that forms a spiral from the center of the disc to its circumference. Each sector is the same physical size and the disc drive constantly varies the rate at which the disc is spinning so that as the read/write head moves toward the center of the disc, the disc speeds up. CLV makes it possible to store more data on a disc. See CAV.
cm
Centimeter. A unit of measurement; 1/100th of a meter or (0.39 inch).
CMF
Creative Music Format.
CMI
Computer-Managed Instruction. The use of computers by teachers in managing instruction programs for students; such as creating and grading tests and monitoring student progress.
CMIP
Common Management Information Protocol. The OSI protocol for network management.
CML
Chemical Markup Language. An application of XML which makes it possible to incorporate chemical symbols into Web pages as easily as text.
CMOS
Complementary Metal Oxide Semiconductor. A kind of integrated circuit used in processors and memories. See CMOS RAM.
CMOS RAM
Complementary Metal Oxide Semiconductor Random Access Memory. A CMOS is a special kind of memory chip that retains its data when power is turned off as long as it receives a small amount of electricity from a battery. In a CMOS, the positive and negative electrical properties of p-type and n-type semiconductors complement each other; as one semiconductor turns on the other turns off. There is no current flow except for charging and discharging of capacitors, and switching; therefore very little power is used. Because of their low power consumption, CMOS chips are useful for main memory in portable computers. The CMOS chip in a personal computer stores a record of what components are installed. Any changes to the basic system configuration, such as the addition or removal of drives, must be recorded in the CMOS setup data.
CMOT
CMIP Over TCP (Common Management Information Protocol over Transmission Control Protocol). A way of using the OSI network management protocol to manage TCP/IP networks. CMOT is no longer in use.
CMYK
Cyan Magenta Yellow blacK. The four standard inks for printing. Four-color printing requires color separations for each of these standard inks.
CNA
Certified NetWare Administrator, a network certification issued by Novell.
CNE
Certified NetWare Engineer. A certification given by Novell for working with networks.
CNI
1. Coalition for Networked Information. A consortium formed to promote networked information resources, to further scholarship and intellectual productivity. 2. Certified NetWare Instructor. A network certification given by Novell.
CNSS
Core Nodal Switching System (Internet).
Coalition Against Unsolicited Commercial
(CAUCE). An organization that works against the distribution of unsolicited commercial e-mail (spam). CAUCE promotes anti-spam legislation and hosts a Web site with information for users about how to deal with spam.
Coalition for Networked Information
(CNI). A consortium formed to promote networked information resources, to further scholarship and intellectual productivity.
coaxial cable
A cable consisting of a single conductor which is surrounded by insulation and a conductive shield. The shield usually is connected to an electrical ground and prevents the cable from picking up or emitting electrical noise. Coaxial cables are used in communications.
COBOL
COmmon Business Oriented Language. A high-level programming language for business data processing, designed by the CODASYL Committee in 1960; the most widely used programming language. It has a natural language style which makes it easy for a programmer who did not write the original program to make corrections and changes.
code
1. A set of symbols that represent assigned, possibly secret meanings. 2. To put a communication into coded form. 3. Computer programming instructions. 4. To write computer instructions.
code division multiple access
(CDMA). A technique of multiplexing, also called spread spectrum, in which analog signals are converted into digital form for transmission. For each communication channel, the signals are encoded in a sequence known to the transmitter and the receiver for that channel.
codec
1. Coder/decoder. A device that converts analog signals to digital to be read by a computer or transmitted over a network, and converts the digital signals back to analog. Sound cards and video cards use this kind of codec. 2. Compression/decompression. A two-step process used on very large multimedia files. Files are compressed to fit on a CD-ROM, then expanded to their original size in order to play them on the computer. MPEG and Indeo are examples of this kind of codec, which may also include analog to digital and digital to analog conversion.
coding
1. Writing program code for a computer. 2. Encrypting.
cold boot
Booting the system from power off. Same as hard boot.
cold fault
An error that occurs immediately after starting a computer.
Cold Fusion
ColdFusion is a visual programming, database and debugging tool. It is
used for building Web applications. ColdFusion offers integration with
databases, e-mail, XML and other enterprise technology.
cold start
Starting the system from power off. Contrast with warm start.
ColdFusion
A web application server. ColdFusion is a server-side scripting language web development tool. It uses HTML-like tags called CFML to enable back-end ODBC database connectivity as well as data manipulation and validation within web pages. Native database connectivity is provided for Oracle or Sybase databases.
collapsed view
A function that condenses a computer document to show only the main headings and hide the remaining text; or, a way of viewing the computer's files that shows only the main directories or folders. The opposite of expanded view.
The bits mapped to each pixel in a color graphic display that determine the pixel's color. The number of bits per pixel is called color depth or bit depth.
color depth
In bitmap graphics, the number of bits per pixel, which determines the number of shades of gray or variations of color that can be displayed by a computer monitor. For example, a monitor with 16-bit color can display 65,536 different colors; a monitor with 24-bit color can display 16,777,216 colors. Multimedia programs and games may require a minimum of 256 colors. See 4-bit color, 8-bit color, 15-bit color, 16-bit color, 24-bit color, 32-bit color.
color graphics
The capability of displaying graphic images in color.
Color Graphics Adapter
(CGA). An early IBM hardware video display standard, with a maximum resolution of 640×200 pixels. It was widely used in the mid-1980s, but then was superseded by EGA.
color lookup table
(CLUT). A table that contains color mixing information, used especially by graphic designers and printers. A formula indicates a color mix by the intensity of red, green and blue in the color. The table can be on paper or in a computer file.
color map
A grid or other display of all the colors available in a computer program. Also called a color palette.
color palette
A grid or other display of all the colors available in a computer program. Also called a color map. The color palette shows the range of colors available to use within a program such as a paint or draw program, photo editing program, or page layout program.
Colossus
The earliest programmable electronic computer, based on ideas from Alan Turing. Max Newman and T.H. Flowers designed and built the computer, which was used by the British government to crack the codes from the German machine Enigma.
column
A vertical set of data, as in a table or spreadsheet. The horizontal set of data is called a row.
column guides
In a page layout program, vertical dotted guide lines that separate columns of text. The number of columns and placement of column guides are specified by the user. Column guides can also be moved with the pointer. The lines do not appear in a printout of the page.
COM port
A serial communications port.
COM printer
Computer output microfilm printer. A page printer that produces a microimage of each page on photographic film.
combination box
A window, often within a dialog box, that has both a scrollable list and a field where text can be entered.
combo box
A window, often within a dialog box, that has both a scrollable list and a field where text can be entered.
Comdex
Computer Dealers Exposition. A computer trade show, held in the spring in Atlanta, GA and in Las Vegas, NV in the fall. New releases of software and hardware are are often first demonstrated at Comdex.
comic-strip orientation
A placing of images so they are aligned at the top and are side by side on the page, like the frames in a comic strip. See cine orientation.
comm
Communication using computers, often via e-mail or real-time text messages.
(CSV). A way of recording database fields in text format; each field is followed by a comma, and often the field is also in quotes. Also called comma-delimited.
command
An instruction given to the computer, by means of a keyboard, punch card, mouse, voice command, or other method.
command and control
(C2). This is a military term. Command and control systems are management information systems that help monitor and control operations; for example, the computer systems that control nuclear weapons.
command key
A key marked with a cloverleaf symbol on the Macintosh. It is used like the shift key, by pressing it at the same time as one or more other keys, to give commands to the computer.
command language
A language designed for giving instructions to a computer’s operating system to perform certain tasks. An example would be a query language. A command language is much more limited than a programming language.
command line
In a command line interface, the user types commands in the space provided directly on the screen using command language. Contrast with graphical user interface.
command line interface
A means of interfacing with a computer by typing in commands on a keyboard.
command prompt
The MS-DOS prompt C:/> which appears on the screen to indicate the operating system is ready to accept an instruction.
command queuing
A function that stores a sequence of commands on the computer and processes the commands one at a time.
command-driven
Having a command-line interface, as opposed to menu-driven. Instructions to the computer must be typed in via the keyboard.
commbot
A program that automatically logs the conversation during an online chat.
commerce
This is a HTTP server that performs business procedures. Information is transfered from the server to the Web browser in a code to keep information secure.
commercial at
ASCII character 64: @ , used in e-mail addresses to separate the addressee from the hostname.
Commercial Internet Exchange
(CIX). A connection point between commercial Internet service providers. Pronounced kix.
commercial software
Software developed for and sold to the general public.
commercialware
Software that is sold to the user for a profit rather than distributed as shareware or freeware.
comming
Communicating using computers, usually via e-mail or real-time text messages.
Commission Internationale de l'Ecla
(CIE). An international committee for the establishment of color standards. The CIE model and the CIE Chromaticity Diagram define the different variations of color.
Commite Consultatif International de Tel
(CCITT). International Consultative Committee on Telecommunications and Telegraphy. Now called International Telecommunications Union (ITU), in Geneva, Switzerland. ITU is one of the organizations working on forming international standards for communication. ITU-T is the arm of ITU responsible for telecommunications standards.
commitment, concurrency, and recovery
(CCR). An OSI application service element that controls operations when two or more computers or applications are working on the same data; CCR makes sure that the operations are either performed completely or not performed at all.
Commodore Business Machines
(CBM). A pioneering company in the personal computer industry; maker of the PET, Commodore, and Amiga computers. The company went bankrupt in 1994. In 1995 the German company Escom AG bought Commodore Business Machines with the intention of manufacturing Amigas once again.
Commodore Dynamic Total Vision
(CDTV). CD-ROM multimedia for Commodore PCs, which can be displayed by a TV monitor.
COmmon Business Oriented Language
(COBOL). A high-level programming language for business data processing, designed by the CODASYL Committee in 1960; the most widely used programming language. It has a natural language style which makes it easy for a programmer who did not write the original program to make corrections and changes.
common gateway interface
(CGI). A way of interfacing computer programs with HTTP or WWW servers, so that a server can offer interactive sites instead of just static text and images.
Common Hardware Reference Platform
(CHRP). An open system standard for PowerPCs, later renamed PowerPC Reference Platform. It allows PowerPC-based computers to run different operating systems, including Mac OS, Workplace OS, AIX, OS/2, Solaris, Taligent, and Windows NT. It designates ports and sockets for compatibility across platforms, and can be used with various buses.
(CLA). A device that converts a digital signal into analog form to send it over a communications line, and converts incoming analog signals back into digital. It also converts a serial transmission to parallel to transmit, and converts incoming parallel signals back to serial form.
Communications Decency Act
(CDA). An amendment to the U.S. 1996 Telecommunications Bill that went into effect in February 1996. The law was intended to protect children from obscenity on the Internet, but many Internet users argued that its language was too vague and that it violated the right of free speech. Protesters against the law turned their Web pages black and displayed blue ribbon icons downloaded from the Electronic Frontier Foundation. In June 1996, a three-judge panel ruled the act unconstitutional. The Justice Department appealed the decision to the U.S. Supreme Court.
communications protocol
A standard way of regulating data exchange between computers, including the rules for data transmission and the formatting of messages. Some communications protocols are TCP/IP, DECnet, AppleTalk, SNA, and IPX/SPX.
comp
Top-level newsgroup category for a newsgroup with discussions about computers.
compact disc
(CD). A 4.72″-diameter disc containing digital audio information, originally developed by Phillips and Sony as a format for very high-fidelity sound. The disc can contain up to 72 minutes of sound. A compact disc is recorded on one side only, and tracks can be played in any sequence. To make the CD, sound waves are sampled 44,056 times per second and converted into digital format, then recorded as microscopic pits which are read by a laser-equipped player. CDs and CD-ROMs are made using the same technology; both have a spiral recording track like a vinyl record, and use constant linear velocity. CDs became instantly popular because of the high quality of digital sound, and replaced vinyl records almost overnight. Audio CDs can be read by special audio CD players, or by CD-ROM players.
Compact Disc Data Base
(CDDB). A public database that has information about CDs; for example, song title, track, and artist information. If your player supports CDDB connections, you can record a CD and then have the tracks titled from the database.
Compact Disc Read-Only Memory
(CD-ROM). An optical disk that is physically the same as an audio CD, but contains computer data. Storage capacity is about 680 megabytes. CD-ROMs are interchangeable between different types of computers.
Compact Disc-Erasable
(CD-E). An erasable CD, which requires a special CD-E drive. The CD-E drive can read and write CD-E disks, CD-R disks and CD-ROM disks.
Compact Disc-Interactive
(CD-I or CD-i) An optical disk that is physically the same as an audio CD, but contains multimedia information (images, sound, etc.) The user can interact with films, games and educational programs. CD-I discs require a CD-I player, which can be used as an accessory to a TV set, and will not play in a standard CD-ROM player.
Compact Disc-Recordable
(CD-R) A recordable CD-ROM which can be read by normal CD-ROM drives; data can only be recorded once onto a CD-R, and cannot be changed.
Compact Disk – Digital Audio
(CD-DA). An audio CD.
Compaq Computer Corporation
A Houston, Texas major manufacturer and vendor of PC compatibles and PC servers, maker of the first PC clone. Compaq Corp. is located at http://www.compaq.com.
compatible
Able to work together. Two hardware devices, such as a computer and printer, can be compatible; or two kinds of software with each other. Software must also be compatible with the hardware it is used with.
compiler
A computer program that translates a high-level programming language into machine language. The compiler usually converts the high-level language into assembly language first, and then translates the assembly language into machine language. The program fed into the compiler is called the source program; the generated machine language program is called the object program.
Complementary Metal Oxide Semiconductor
(CMOS) . A kind of integrated circuit used in processors and memories. See CMOS RAM.
component
An element within a larger system; a component could be hardware or software.
Composite Key
Used in database management systems as a key which has two or more fields in the columns in the table, or in a file.
compositor
Typesetter.
compound document
A document containing information from more than one program. A compound document might contain text from a word processor, an image from a draw or paint program, and a table from a database.
compound tags
Tags that require an opening and closing code; for example, the HTML tags <CENTER> and </CENTER>. Text and other items between these two tags will be centered on the page.
Compress
A compression program for DOS and UNIX. It creates compressed files with the .Z suffix.
compress
To code data in a way that makes it more compact. Compressed files save storage space and are faster to transmit. Some popular compression programs are Stuffit, Stacker, PKZIP, and Compact Pro.
compression
The temporary coding of data in a way that saves storage space or transmission time. Most text files can be compressed to about half their normal size. Graphics can be compressed to 10 percent of their original size.
compu-rag
Computer magazine.
compu-slang
Computer slang; informal words and phrases that have come into use among computer programmers and users.
CompuServe
An online service offering news and weather, sports, entertainment, airline schedules, stock market reports, medical information, and online publications. Users have access to bulletin boards, conferencing, e-mail, discussion forums and special interest groups, and the Internet. To send mail to a CompuServe user from outside CompuServe, change the comma to a period and add @compuserve.com. For example, 12345,678 becomes [email protected]
compuserve.com
Internet domain address of CompuServe.
compute
1. To calculate or figure. 2. To use a computer.
computer
An electronic device that has the ability to store, retrieve, and process data, and can be programmed with instructions that it remembers. The physical parts that make up a computer (the central processing unit, input, output, and memory) are called hardware. Programs that tell a computer what to do are called software.
Computer
The journal published by the IEEE (Institute of Electrical and Electronics Engineers) Computer Society.
computer aided design
(CAD). In fields such as engineering and architecture, using computer graphics to do work that formerly would have been done with pencil and paper. CAD requires a high-resolution monitor and special software.
computer aided design & drafting
(CADD). CAD systems with features added for drafting.
computer aided design/computer aided man
(CAD/CAM). A combination of CAD and CAM. For example, a designer creates a 3-dimensional representation of an object, with the help of the computer, and then the computer programs instructions for automated manufacture of the object and controls the manufacturing process.
computer aided engineering
(CAE) Using computers to help with engineering design work.
computer aided language learning
(CALL). The use of computers in learning a language.
computer aided software engineering
(CASE). The use of computers to help with the analysis, design, implementation or maintenance of software. Also called Computer Assisted Software Engineering.
Computer and Business Equipment Manufact
(CBEMA). A Washington, D.C. organization that develops standards for computers and business equipment worldwide.
computer assisted software engineering
(CASE). The use of computers to help with the analysis, design, implementation or maintenance of software. Also called Computer Aided Software Engineering.
computer automatic virtual environment
(CAVE). A reality simulation in which the user does not wear goggles, but images are projected on the walls and ceiling giving an illusion of 3-D reality.
computer conferencing
Communication between people at different geographic locations by means of text and graphic messages sent between interconnected computers.
computer crime
A crime committed using a computer or data stored on a computer.
Computer Dealers Exposition
(COMDEX). A computer trade show, held in the spring in Atlanta, GA and in Las Vegas, NV in the fall. New releases of software and hardware are are often first demonstrated at Comdex.
Computer Emergency Response Team
(CERT). An organization formed by DARPA in 1988 after the Internet worm incident. CERT watches for threats to Internet security, educates the public about computer security issues, and conducts research to improve the security of existing systems. CERT issues advisories and provides 24-hour technical assistance in response to computer security emergencies.
computer games
Games played on the computer. Computer games may be played from a floppy disk or CD-ROM, by means of e-mail, or online via BBS or Internet. There are single-player and multi-player games. The term is sometimes used to refer to those games that have a visual interface, as opposed to text-based games like RPGs and MUDs. Some popular computer games are DOOM, Wolfenstein, and Myst.
computer geek
A person who is fanatically interested in computers. In the positive sense, the word can mean someone who is very knowledgeable about computers. In the negative sense, it implies someone who has few social skills, and is only comfortable communicating with computers.
computer generations
The development of computers began in the late 1940s and early 1950s with huge mainframes that used vacuum tube technology. The second generation of computers were built with discrete transistors, from the mid-1950s through the mid-1960s. Third-generation computers were built using integrated circuits after the mid-1960s; during this time period, minicomputers were developed. The fourth generation of computers are the microcomputers which use large-scale integration or very large-scale integration. The fifth generation of computers, beginning in the late 1990s, is expected to greatly expand the use of artificial intelligence. See also first generation computer, second generation computer, third generation computer, fourth generation computer, fifth generation computer.
computer graphics
The creation, editing, or publishing of pictures by means a computer.
Computer Graphics Metafile
(CGM). An ANSI standard format for exchanging graphics files between applications, in both vector and raster formats.
computer hardware
The hardware is the physical part of a computer system; the machinery and equipment. Software means the programs that tell the computer what to do.
Computer Incident Advisory Capability
(CIAC). This group assists the Department of Energy in its information protection efforts by providing computer security incident response services.
computer literate
Having a working knowledge of computers and software; does not imply extensive technical expertise.
computer output microfilm printer
(COM printer). A page printer that produces a microimage of each page on photographic film.
computer phobia
Literally, fear of computers. Anxiety about learning to use computers, or not being able to learn successfully; often used simply to mean resistance to learning the new skills required by increasing use of computers in the workplace.
Computer Professionals for Social Respon
(CPSR). A public-interest alliance of computer scientists and others interested in the impact of computer technology on society. As concerned citizens, they direct public attention to critical choices concerning the applications of computing and how those choices affect society.
computer program component
(CPC). A routine or module within a larger program.
computer programmer
A person who writes instructions (programs) for computers.
computer role playing game
(CRPG; also called RPG). A game which may be played on a computer or with pen and paper, in which the players act out a different reality. Classic role-playing games involve creating a character, assigning a set of attributes such as strength, dexterity, willpower, charisma, etc., and moving the character through adventures in a fantasy, historical, or futuristic environment, usually containing enemies to fight and treasures to find. The game is often led by a gamemaster or dungeonmaster who does not play a character but who has keys to the game, hidden rules, and a secret map that the players can't see; the gamemaster tells a player what each room looks like upon entering, when he has run into something invisible, whether he hit the dragon enough times to kill it, etc. The first gamemaster is usually the designer of the game.
Computer Security Act
An act signed in January 1988 by President Reagan, establishing guidelines for the security and privacy of information in U.S. government computer systems, the training of federal employees in computer security practices, and the differences between computer security in defense-related and civilian agencies of government.
computer software
Software is the programs that tell a computer what to do. Hardware is the physical part of a computer system; the machinery and equipment.
computer virus
A program that infects a computer by atttaching itself to another program, and propagating itself when that program is executed. A computer can become infected by files downloaded over a network, or by the installation of new software or floppy disks that are infected with viruses. Some viruses are only pranks, and perform harmless actions like displaying a screen with a joke message on it. Others can destroy files or wipe out a hard drive. To avoid damage from viruses, write-protect the boot disk and other important disks, check new software or disks for viruses, and have virus protection software installed on the computer at all times. Disinfectant programs must be updated periodically because new viruses get into circulation over time. There are some virus protection programs available on the Internet for free. Disinfectant for Macintosh, written by John Norstad of Northwestern University, is freeware; McAfee Anti-Virus for PC is a shareware program. Knowingly spreading a computer virus is a crime punishable by law. See also Trojan horse and worm.
Computer-Aided Instruction
(CAI) Using computers as aids for instructional purposes.
computer-aided manufacturing
(CAM). The use of computers in manufacturing, including automated manufacture.
computer-aided planning
(CAP). Using computers to organize data and make plans; normally used in business and industry.
computer-aided publishing
Electronic publishing.
Computer-Aided Software Testing
(CAST). The use of an automated program for software testing.
computer-based training
(CBT) Training through use of a computer.
computer-human interface
(CHI). The kind of interface between computer and human determines how easy the computer is to use.
computer-managed instruction
(CMI). The use of computers by teachers in managing instruction programs for students; such as creating and grading tests and monitoring student progress.
Computer+Science Network
(CSNET). A large computer network, including universities, research labs, and some commercial enterprises. It originated in the United States, and has some members in other countries. CSNET merged with BITNET to form CREN.
computerese
Technical jargon used by computer enthusiasts.
computerize
1. To equip with computers. 2. To control by means of computers. 3. To input and store in a computer.
Computerville
A Computer Currents site on AOL’s Digital City.
computing
The programming and use of computers.
Computing Scale Company
A Dayton, Ohio company that made scales and food slicers. It merged with other companies in 1911 to form the Computing-Tabulating-Recording Company, which in 1924 was renamed the International Business Machines Company (IBM).
Computing Systems Technology Office
(CSTO). A U.S. Department of Defense (DoD) agency. In 1991, the Information Science and Technology Office (ISTO) was divided into CSTO and the Software and Intelligent Systems Office.
Computing-Tabulating-Recording Company
A company formed in 1911 from a merger of the Tabulating Machine Company, International Time Recording Company, Computing Scale Company, and Bundy Manufacturing. In 1924 the Computing-Tabulating-Recording Company was renamed the International Business Machines Company (IBM).
Conceptual Knowledge Markup Language
(CKML). An application of eXtensible Markup Language (XML) which extends the capabilities of Ontology Markup Language (OML). These markup languages enable authors to annotate World Wide Web documents with machine-readable knowledge, thus improving the ability of intelligent agents to gather information.
conditional branch
A program instruction that tells the computer to jump to another location in the program if a specified condition is met.
conductor
A material through which electrical current can flow.
conduit
A pipe which protects electric wires and cables.
conference call
A form of teleconferencing in which participants are connected by telephone lines and can communicate by voice and fax.
CONFIG
Configuration.
Config PPP
A Macintosh control panel which contains PPP instructions such as port speed, modem unit string, telephone number, server, etc., configured by the user, and which is opened to establish a PPP connection.
CONFIG.SYS
A file found in the root directory of DOS and OS/2 systems that is used to load drivers and configure the system. Some parameters which are set by CONFIG.SYS are the number of files that can be opened at once, the memory available for disk buffers, the number of disk drives, etc. The user can modify CONFIG.SYS, and it is automatically adjusted by some software installation programs, to enable the software to work with that system.
configurability
How much a system can be changed or customized.
configuration
The way a computer is set up, which includes the hardware (type of CPU, peripherals, etc.) and the software.
configure
To set up the software or hardware of a computer. A computer can be configured differently for different uses; for example, peripherals or memory can be added or taken away; software can be installed or uninstalled; software preferences can be adjusted for different uses.
ConflictNet
A network sponsored by the Institute for Global Communications for the purpose of improving worldwide communication among groups and individuals involved in conflict resolution.
connect time
The amount of time a computer is connected to an online service or other network. Some commercial services charge by the hour. Nonprofit BBSs are free, but may limit each user's connect time per day so everyone gets a chance to use the services.
Connection Oriented Network Service.
(CONS). Connection-oriented communication takes place in three phases: connection establishment, data transfer, and connection release. See connection-oriented.
connection-oriented
A way of transmitting data that requires a connection be established first. After connection is established, the data is transferred, then the connection is released. Examples of connection-oriented transmission are Transmission Control Protocol (TCP) and most wide area networks (WANs). Contrast connectionless.
connectionless
A kind of communication which takes place without first establishing a connection. A means of data transfer in which each data packet has source and destination information, so a direct connection is not required. Internet Protocol and most local area networks use connectionless transmission, as opposed to connection-oriented.
Connectionless Network Protocol
(CLNP). The OSI protocol for OSI Connectionless Network Service. CLNP is the OSI equivalent to the Internet Protocol (IP), and has been called ISO IP.
Connectionless Transport Protocol
(CLTP). The OSI equivalent of UDP. A type of interconnection in which communication takes place without first establishing a connection. See connectionless.
CONS
Connection-Oriented Network Service. Connection-oriented communication takes place in three phases: connection establishment, data transfer, and connection release. See connection-oriented.
Conseil Europeen pour la Recherche Nucle
CERN (European Laboratory for Nuclear Research). A high-energy physics research center in Geneva, Switzerland, where the World Wide Web was developed.
console applications
In Linux, applications that are run directly from the Linux command prompt.
constant angular velocity
(CAV). The writing or reading mode used with a hard disk, floppy disk, or laserdisc. The disk rotates at a constant speed, and the number of bits in each track is the same, but because the inner tracks are smaller in circumference than the outer tracks, their density is less. CAV wastes disk space this way compared with constant linear velocity (CLV), but makes data retrieval fast and is a good way to store high-resolution photos or video.
constant linear velocity
(CLV). A way of reading and writing data used by CD-ROMs and CDs. Instead of having several tracks arranged in concentric circles, data is contained in a single track that forms a spiral from the center of the disc to its circumference. Each sector is the same physical size and the disc drive constantly varies the rate at which the disc is spinning so that as the read/write head moves toward the center of the disc, the disc speeds up. CLV makes it possible to store more data on a disc. See CAV.
content-free
Having no content. This expression can be used to refer to a communication that doesn't really communicate anything, such as a lengthy speech that has no substance.
context-free
Not dependent on context; a context-free grammar is one in which the syntax of a symbol is the same regardless of its context (that is, regardless of what other symbols occur before it or after it).
context-sensitive help
A software feature that gives help related to the specific program, command or dialog box that is open.
continuous forms
A continuous roll or stack of paper forms that are fed through a tractor-feed printer as one long sheet of paper. The forms have perforations between them so they can be separated into individual sheets after printing.
contrast
The degree of difference between the lightest and darkest areas on a computer screen.
Control Data
Computer manufacturer of supercomputers; its computers were especially used for government, military, and scientific applications.
control key
On the computer keyboard, the key marked Ctrl or Ctl. This key is used in combination with other keys pressed at the same time to give instructions to the computer, sometimes providing a shortcut to using menu commands. For example, Ctrl + S is used in some programs to save the current file.
control language
(CL ). A language by which a user gives commands to a computer to perform certain tasks. It is more limited than a programming language.
control menu box
In Windows, a little box at the top left corner of each window, which closes the window when the user double-clicks on it.
control panel
A window on the computer that is used to adjust settings such as mouse speed, screen colors, speaker volume, communications, etc.
control strip
A strip of icons at the bottom of the desktop in the Mac OS environment, which allows the user to quickly access certain controls including AppleTalk, SCSI devices, monitor settings, printers, sound, and file sharing.
Control-Alternate-Delete
Configuration of keystrokes for rebooting a PC. The CTRL and ALT keys are held down while pressing the DEL key.
Control-C
ASCII character 3: break, or interrupt. Control-C is used in Unix, MS-DOS, and some other operating systems to abort a running program.
Control-S
ASCII character 19. In many computer programs Ctrl + S is a fast way to save the current file, instead of selecting Save from a pull-down menu.
Control-U
ASCII character 21. In some word processing programs, Ctrl + U turns on the underline function.
conventional encryption
A form of encryption in which sender and receiver share with each other a secret key to decrypt messages sent between them. Conventional encryption, also called private key encryption, is different from public key encryption in which both sender and receiver have the public key, but each has a private key which is not shared.
conventional memory
The first 640K of PCRAM, which is used to store DOS and application programs. See also Upper Memory Area, Upper Memory Block, High Memory Area, extended memory, expanded memory.
conversion program
A program that changes a file from one format to another.
conversion rate
The rate at which users go from viewing an ad on the Web to taking a desired action on the advertiser's site, such as registering or buying something. This statistic is used in combination with click rate to determine the effectiveness of advertising.
cookie
A cookie is a set of data that a website server gives to a browser the first time the user visits the site, that is updated with each return visit. The remote server saves the information the cookie contains about the user and the user's browser does the same, as a text file stored in the Netscape or Explorer system folder. Not all browsers support cookies. Cookies store information such as user name and password and what parts of the site were visited; this information can be updated with each visit. The browser only shares each cookie with the server that originated it; other servers can only read their own cookies. Netscape can be set up to alert the user when a cookie is being sent so the user can accept it or not, by means of the Network Preferences window. There are also downloadable applications that eat cookies such as Cookie Killers, Cookie Monster (Mac), and Kill Cookie Batch File (PC).
Cookie Killers
A program that eats HTTP cookies, that is, removes them from the computer. See cookies.
Cookie Monster
A Mac program that eats HTTP cookies, that is, removes them from the computer. Cookie Monster can be initiated at startup to eliminate all cookies from the last session. See cookies.
cookies
A cookie is a set of data that a Web site server gives to a browser the first time the user visits the site, that is updated with each return visit. The remote server saves the information the cookie contains about the user and the user’s browser does the same, as a text file stored in the Netscape or Explorer system folder. Not all browsers support cookies. Cookies store information such as user name and password and what parts of the site were visited; this information can be updated with each visit. The browser only shares each cookie with the server that originated it; other servers can only read their own cookies. Netscape can be set up to alert the user when a cookie is being sent so the user can accept it or not, by means of the Network Preferences window. There are also downloadable applications that eat cookies such as Cookie Killers, Cookie Monster (Mac), and Kill Cookie Batch File (PC).
Cooperation for Open Systems Interconnec
(COSINE). A program sponsored by the European Commission to use OSI in connecting European research networks.
cooperative multitasking
A multitasking environment in which a program running in the background can only receive processing time when the program in the foreground allows it; an application can give up control of the processor to another application only at certain points, such as when it is ready for input from the keyboard. This method of multitasking may allow one program to dominate the computer's resources so other programs have limited access to the CPU. It is also called non-pre-emptive multitasking. Contrast with preemptive multitasking.
coordinate graphics
A way of representing pictures by designating coordinates and drawing lines or geometric shapes in relation to them. Coordinate graphics are different from bitmapped graphics, in which an image is stored as a collection of pixels. In coordinate graphics, the image is saved as a file containing instructions for drawing it. One advantage of coordinate graphics over bitmapped graphics is that a picture can be enlarged or reduced without losing quality. Another difference is that in coordinate graphics, the elements of a picture (circles, squares, etc.) remain independent objects which can be edited and moved around, whereas in bitmapped graphics, once the elements are drawn they become part of the overall pattern of pixels. A coordinate graphics image also requires less memory than a bitmapped graphics image, which requires a specific memory location for each pixel.
Coordinating Committee for Intercontinen
(CCIRN). A committee made up of major North American and European research organizations, whose goal is international cooperation among research networks. Its membership includes the United States Federal Networking Council (FNC), the European Association of Research Networks (RARE), and other research organizations.
Copernicus
The code name under which the Navy is reformulating its command and control structures from the viewpoint that information is a weapon.
copper-distributed data interface
(CDDI). A token ring network similar to FDDI, but it uses copper cable, and is limited to distances of 50 to 100 meters.
coprocessor
A computer processor which speeds up operation of the computer by helping the main processor, or CPU. For example, the floating point coprocessor handles floating point operations when required. There are also graphics coprocessors and networking coprocessors.
copy
1. To make a duplicate of a disk, file, group of files, part of a file, etc. 2. A duplicate.
copy protection
A number of methods devised by software manufacturers to stop people from making unauthorized copies of software. One method is a serial number that must be entered in order to use the program; another is a hardware key that must be plugged into the back of the computer.
copyleft
A copyrighting concept created by the GNU project. The simplest way to make a program free is to put it in the public domain, uncopyrighted. This allows people to share the program and any improvements they make on it, but it also allows anyone to convert the program into proprietary software. If someone makes changes and distributes the changed program as a proprietary product, the people who receive the program in that form do not have the freedom that the original author gave them; the middleman has stripped it away. The aim of the GNU project is to give all users the freedom to redistribute and change GNU software. Copyleft guarantees that every user has this freedom. Instead of putting GNU software in the public domain, GNU first copyrights it, and then specifies in the distribution terms that everyone has the rights to use, modify, and redistribute the program's code or any program derived from it, but only if they pass along the freedom to further copy and change it. These distribution terms are contained in the GNU General Public License (GNU GPL).
CORBA
Common Object Request Broker Architecture. A program that helps transfer messages to and from objects between various platforms in a distributed environment.
core gateway
One of the gateways operated by the Internet Network Operations Center at Bolt, Beranek and Newman (BBN). The core gateway system originally formed a central part of Internet routing; all groups had to advertise the paths to their networks from one of the core gateways.
Corel Corporation
An Ottawa, Ontario, software company. CorelDraw and Corel Ventura are two popular products.
Corel Ventura
A desktop publishing program for Windows from Corel Corporation.
CorelDraw
A suite of graphics and desktop publishing applications for Windows from Corel Corporation; it includes Corel Ventura.
COREtest
A DOS disk benchmarking program created by CORE International.
Corporation for Open Systems
(COS). A nonprofit consortium of vendors and user groups that sponsors conformance testing, certification, and promotion of OSI (Open Systems Interconnection) products, with the aim of developing international standards for networking systems.
A file so damaged that the computer is unable to read it. A file could be corrupted by a virus, or by software or hardware failure.
COS
1. Corporation for Open Systems. A nonprofit consortium of vendors and user groups that sponsors conformance testing, certification, and promotion of OSI (Open Systems Interconnection) products, with the aim of developing international standards for networking systems. 2. The cosine function in FORTRAN, BASIC, and other programming languates.
COSINE
Cooperation for Open Systems Interconnection Networking in Europe. A program sponsored by the European Commission to use OSI in connecting European research networks.
Cougar
The code name for an experimental extension of HTML 3.2 to add support for style sheets, scripting, the object tag, internationalization and enhanced forms.
coulomb
A unit of electrical charge equal to 6.26 x 10 to the 18th degree electrons.
country code
A code that indicates from what country a Web site or e-mail originates. Also called country domain name. The country code is part of the e-mail address or URL. Examples: .ca = canada, .au = australia, .uk = united kingdom, .fr = france, .il = israel .
Courier
A monospaced typeface that looks like type from a typewriter. It
is often used for business letters.
courseware
The programs and data used in computer-based training.
cp
A UNIX command to copy a file onto a file or into a directory.
CPC
Computer Program Component. A routine or module within a larger program.
cpi
Characters Per Inch. A measure used with typefaces.
CPM
(Cost Per M). The cost per thousand ad views for a banner ad on a Web page.
1. Characters Per Second. Used to measure printer speed. 2. Cycles Per Second.
CPSR
Computer Professionals for Social Responsibility. A public-interest alliance of computer scientists and others interested in the impact of computer technology on society. As concerned citizens, they direct public attention to critical choices concerning the applications of computing and how those choices affect society.
CPU
Central Processing Unit. The CPU controls the operation of a computer. Units within the CPU perform arithmetic and logical operations and decode and execute instructions. In microcomputers, the entire CPU is on a single chip.
CPU cache
A memory bank between the main memory and the CPU, which enables the computer to read data and execute instructions faster. The CPU cache is static RAM (SRAM); main memory is dynamic RAM (DRAM). See cache and disk cache.
CPUBM
Central Processing Unit Benchmark. A freeware program for Windows 95/98 that tests a system to measure its CPU performance. The tested system is compared to twenty other systems in the program’s internal database.
CR
Carriage Return. The return key or the carriage return instruction which is entered by pressing the key.
cracker
A person who breaks into computer systems, using them without authorization, either maliciously or to just to show off.
cramming
Cheating telephone service customers by adding unauthorized charges to their phone bills.
crash
A sudden, major failure of a computer because of hardware or software problems; often causes loss of data.
crash into
To break through security to gain unauthorized access to a private network.
crawler
A computer program that retrieves online documents and the references linked to them, and may perform indexing.
Cray Research, Inc.
A U.S. company known for manufacture of mainframe supercomputers.
Cray, Seymour
A designer of supercomputers who founded Cray Research.
CRC
Cyclic Redundancy Check. A number derived from a block of data, and stored or transmitted with the data in order to detect any errors in transmission. It is similar to a checksum, but more complicated. A cyclic redundancy check is often calculated by adding words or bytes of the data. The receiving computer recalculates the CRC from the data received and compares it to the value originally transmitted; if the values are not the same, it indicates a transmission error. The CRC is called redundant because it adds no significant information to the transmission itself.
Creative Labs
A Milpitas, California manufacturer of sound cards; producer of the Game
Blaster stereo sound board, the Sound Blaster card, and the Sound Blaster
Multimedia Upgrade Kit.
CREN
The Corporation for Research and Educational Networking. A corporation formed by the merging of BITNET (Because It’s Time Network) and CSNET (Computer+Science Network).
crippleware
Demonstration software which is distributed in a limited form in order to entice trial users to buy it; for example, a game in which the trial user can only play the first couple of levels.
critical error
An error that makes it impossible for the current running program to continue.
Control Read Only Memory. A kind of storage in the control block of some microprocessors.
crop marks
Horizontal and vertical lines at the outside corners of camera-ready artwork which show where it should be cut (cropped) down to its final size.
cross-compiler
A compiler which runs on one type of computer and produces machine code for a different type of computer. See native compiler.
Cross-Interleaved Reed-Solomon Code
(CIRC). A technology used in compact discs for error detection and correction.
cross-platform
1. Available for more than one type of computer. For example, a cross-platform program might be available for PC, OS/2, and Macintosh. 2. A computer that can understand, and run programs in, different operating systems; for example, a PowerPC that can run Macintosh and Windows programs.
cross-post
Posting a single article to several newsgroups at the same time — generally considered inconsiderate by newsgroup members.
CRPG
Character Role Playing Game or Computer Role Playing Game. (Also called simply RPG). A game which may be played on computer or with pen and paper, in which the players act out a different reality. Classic role-playing games involve creating a character, assigning a set of attributes such as strength, dexterity, willpower, charisma, etc., and moving the character through adventures in a fantasy, historical, or futuristic environment, usually containing enemies to fight and treasures to find. The game is often led by a gamemaster or dungeonmaster who does not play a character but who has keys to the game, hidden rules, and a secret map that the players can't see; the gamemaster tells a player what each room looks like upon entering, when he has run into something invisible, whether he hit the dragon enough times to kill it, etc. The first gamemaster is usually the designer of the game.
CRT
Cathode ray tube, used in computer monitors.
crudware
A term for low-quality freeware available on bulletin board systems and other places. The software is free, but there is no guarantee of performance and no support.
crunch
To process data (sometimes called number crunching); or to compress data (file crunching).
crypt
A UNIX encryption system which is based on a the WWII German Enigma cipher, broken by Polish and British cryptographers during the war. There are programs available for decryption, so it is not a reliable encryption system to use when security is important.
cryptanalysis
The theory and art of cracking codes.
crypto anarchy
A possible state of the political and economic system that could result from technologies like encryption, anonymous e-mail, digital pseudonyms, electronic cash, etc.
cryptography
The technology of encoding information so it can only be read by authorized individuals.
cryptology
The scientific study of coding and decoding information.
cryptosystem
A system used for the encryption and decryption of data.
CS
Clear to Send. A modem status signal which means the modem is ready to accept data from the local computer, which it will then transmit to a remote computer.
CSC
Customer Support Consortium. A group of leading technology companies working together to find ways to improve customer support.
CSE
Certified Systems Engineer. Certification level from Microsoft for technical specialists in Windows NT and other Microsoft software.
Compressed Serial Line Internet Protocol. A SLIP version in which the data is compressed for faster transmission.
CSMA/CD
Carrier Sense, Multiple Access, Collision Detection. Ethernet packets are transmitted using CSMA/CD, which means the sending computer waits for the line to be free before sending a message, then sends; if two computers accidentally transmit at the same time and their messages collide, they wait and send again at different times.
CSNET
Computer+Science Network. A large computer network, including universities, research labs, and some commercial enterprises. It originated in the United States, and has some members in other countries. CSNET merged with BITNET to form CREN (The Corporation for Research and Educational Networking).
CSS
1) Content Scrambling System. The copy protection system used inside DVD players to protect a player's digital media. 2) Cascading style sheets. A style sheet mechanism that has been specifically developed for Web page designers and users. Style sheets describe how documents are presented on screens, in print, and even in spoken voice. Style sheets allow the user to change the appearance of hundreds of Web pages by changing just one file. A style sheet is made up of rules that tell a browser how to present a document. Numerous properties may be defined for an element; each property is given a value. Examples are font properties, color and background properties, text properties, box properties, classification properties, and units. The term cascading refers to the fact that more than one style sheet can be used on the same document, with different levels of importance. There are differences between CSS and XSL (Extensible Style Language). Both languages can be used with XML, but only CSS can be used with HTML. XSL, however, is a transformation language, and can be used to transform XML data into HTML/CSS documents on a Web server.
CSTO
Computing Systems Technology Office. A U.S. Department of Defense (DoD) agency. In 1991, the Information Science and Technology Office (ISTO) was divided into CSTO and the Software and Intelligent Systems Office.
CSV
Comma-separated values. A way of recording database fields in text format; each field is followed by a comma, and often the field is also in quotes.
CTO
Chief technology officer or chief technical officer. The executive who directs an organization in matters pertaining to technology.
CTS
Clear To Send. A modem status signal which means the modem is ready to accept data from the local computer, which it will then transmit to a remote computer.
CU-SeeMe
A videoconferencing program for use with personal computers on the Internet, developed at Cornell University (“CU”). CU-SeeMe supports both direct connections between clients and multi-user conferencing.
CUG
Commodore User Group.
current
Flow of electrical charge, measured in amperes. An ampere = 6.25 x 1018 electrons per second.
cursor
The movable symbol on a computer screen that shows where the user is working, whether typing in text, drawing lines, or moving design elements around. The cursor can be moved with the arrow keys or a mouse. It usually appears in text programs as a blinking dash or rectangle, or an arrow. In graphics programs the cursor is often called a pointer, and can take many different shapes such as a brush, pencil, or hand.
cursor keys
Arrow keys that move the cursor up, down, right, and left on the computer screen. On many computers the cursor can also be moved with a mouse.
Customer Relationship Management (CRM)
Customer Relationship Management is a technology designed to help companies maintain interaction with their customers. With more and more companies doing business electronically, establishing relationships with customers, as well as monitoring customer service and satisfaction, has become more complicated and challenging. Software companies are developing products — such as help-desk software, e-mail organizers and Web development applications to help companies stay in contact with their customers
customer support
Service for customers that is provided by computer vendors and hardware and software manufacturers, usually by telephone or e-mail.
Customer Support Consortium
(CSC). A group of leading technology companies working together to find ways to improve customer support.
cut
In document editing, to remove a block of material, which is then held in the clipboard for deletion or pasting elsewhere.
cut and paste
Deleting a block of material (text or graphics, or both) from one place and moving it to another place. The expression is taken from production room layout, where originally cutting and pasting was done by hand.
CVF
Compressed Volume File.
CVGA
Color Video Graphics Array.
cw
Clockwise.
CWIS
Campus-Wide Information System. Publicly available computer systems provided in kiosks on university campuses where users can access directories, databases, bulletin boards, calendars, and other information services.
cyber-
A prefix taken from the word cybernetics (Greek kybernan, to steer or govern), and attached to other words having to do with computers and communication.
cyberattack
An attack on, or by means of, information technology.
cybercafe
A cafe where online services are available. Patrons can surf the Internet or play computer games, while meeting others with similar interests and sharing computer knowledge. Cybercafes originated in New York and are now available around the world; travelers can use cybercafes to connect to online services when away from home.
CyberCash
Electronic cash; a way of transferring funds in online transactions. Now in its trial period, but expected to become widespread soon.
cybercast
Using the World Wide Web to broadcast information or entertainment. Cybercasting uses push technology, in which the information is transmitted regardless of whether it is requested. (Another example of push technology is e-mail.) Another word for Web cast.
cybercitizen
A citizen of the worldwide online community.
cyberculture
The culture that has formed among those who use the Internet and other networks to communicate, and have formed social groups which meet and interact online and may never meet in real life. Cyberculture has its own customs, etiquette, mythology, and ethics.
cyberdefense
Defense of information systems against cyberattack.
cyberjunkie
A person who is addicted to computers and being online.
cybernation
The automatic control of a process or task by computers.
cybernaut
A cyberspace navigator; a person who travels in cyberspace.
cybernetics
The study of communication and the control of complex systems, especially concerned with comparing automatic control systems such as computers and the human nervous system.
cyberporn
Pornographic material available online; a major concern of parents, legislators, and free speech advocates since the Internet became available to the general public.
cyberpunk
A subgenre of science fiction which often describes post-apocalyptic or urban jungle environments populated by high-tech renegades, who in some cases use computer networks to connect minds in a semi-mystical way. The word cyberpunk now often refers to a fan of cyberpunk fiction, hackerdom, and Internet surfing, who follows the punk fashion trends of black leather, fluorescent hair and pierced body parts.
cybersoap
An interactive soap opera on the Internet.
cyberspace
A term coined by author William Gibson in his novel Neuromancer. The prefix cyber- comes from the Greek word kybernan, which means to steer or govern, and is used with words related to cybernetics (communication and the control of complex systems, especially in comparing automatic control systems such as computers with the human nervous system). Cyberspace refers to the electronic space created by computers connected together in networks like the Internet. In a broader sense, cyberspace has been used to mean the world of interconnected minds. The places that can be visited by means of a computer network do not really have a physical existence, but they have some kind of existence; in the same way, the places and characters in literature and mythology, though they never exist “in real life,” have an existence in the domain of the human collective consciousness.
cybersquatter
A person who buys a domain name corresponding to a famous brand name or trademark, hoping to resell it for big bucks when the company wants to open a Web site.
cybersquatting
The practice of registering a domain name using someone else’s trademark, in the hope of later selling the domain to the trademark owner at a high price. Some domain name speculators have created offensive or pornographic sites using famous trademarked names. Legislation is underway to make the practice illegal.
cyberterrorism
A terrorist attack on, or by means of, information systems.
CyberZine
A combination magazine and online World Wide Web guide.
cyclic redundancy check
(CRC). A number derived from a block of data, and stored or transmitted with the data in order to detect any errors in transmission. It is similar to a checksum, but more complicated. A cyclic redundancy check is often calculated by adding words or bytes of the data. The receiving computer recalculates the CRC from the data received and compares it to the value originally transmitted; if the values are not the same, it indicates a transmission error. The CRC is called redundant because it adds no significant information to the transmission itself.
cypherpunk
A network user who likes to use encryption for privacy.
Cyrix
A manufacturer of microprocessors.
D/A conversion
Digital to Analog conversion. The translation of digital information (1s and 0s) into analog information, such as sound waves.
D/L
Download. To receive a data transmission.
D1
Broadcast-quality digital video format that is “raw,” or not compressed. Uses 1MB for each frame.
D2
Broadcast-quality digital video format that integrates with analog equipment.
D3
Broadcast-quality digital video format recorded on half-inch tape. Is a cheaper alternative to D1 recording.
D4
Framing format for T1 transmission. Places 12 T1 frames into a superframe.
D5
Broadcast-quality digital video format recorded on half-inch tape. Cheaper alternative to D1 recording.
DA
Desk Accessory. A small, useful program that is analogous to an item on a real office desktop, such as a clock, calculator, calendar, and message pad. Macintosh desktop accessories can be made easily available by putting them in the Apple menu. Windows desk accessories are in the Accessories group.
DAC
Digital to Analog Converter. An electronic circuit that converts digital information (for example, from a CD or CD-ROM) into analog information, such as sound and audio signals.
DAD
1. Database Action Diagram. Describes the processing of data in a database. 2. Digital Audio Disk, or compact disk (CD).
daemon
A UNIX program that runs continuously in the background, until it is activated by a particular event. This word is often used to refer to programs that handle e-mail. The word daemon is Greek for “an attendant power or spirit.”
DAI
Distributed Artificial Intelligence.
daisy chain
A configuration in which devices are connected to each other in sequence, like a chain of daisies.
daisywheel printer
A impact printer that uses a rotating plastic wheel with the type characters on it. The wheel spins to line up the correct character to print. Daisywheel printers produced high-quality type, and were common in the 1980s but fell out of use when laser printers became affordable.
DAL
Data Access Language. An Apple database interface that enables Macintosh computers to access certain databases on other computers and platforms.
DAM
(Digital Automatic Music). DAM CDs contain music in both MP3 and standard CD audio format. They can be played from an MP3 player or CD player. They often include special releases not available elsewhere.
DAM CD
(Digital Automatic Music). DAM CDs contain music in both MP3 and standard CD audio format. They can be played from an MP3 player or CD player. They often include special releases not available elsewhere.
dancing baloney
Animated images and other small moving objects that decorate a Web site.
Dante
A nonprofit organization that aids European research communities in enhancing network capabilities, primarily focusing on building a high-speed computer network infrastructure. Located at www.dante.net. Established in 1993.
DAP
Directory Access Protocol. In an X.500 directory system, the protocol used in communications between a Directory User Agent (DUA) and a Directory System Agent (DSA).
dark fiber
Fiber-optic cable when it is not carrying a signal. When a signal is being carried, it is called lit fiber.
DARPA
Defense Advanced Research Projects Agency. The Federal agency that began as ARPA, and started the Internet. It became ARPA again in 1990.
DASD
Direct Access Storage Device. A peripheral device for a mainframe computer, such as a disk or drum, that can be directly addressed.
DAT
Digital Audio Tape. A kind of magnetic tape originally designed for audio format, now also used in computers to back up data. DAT cassettes are about the size of audio cassettes, and can store up to 12GB.
data
Information; raw facts. Data can be input into a computer and processed in various ways. For a computer to process data, it must be translated into a form the computer can handle. The smallest discrete element of data that a computer can understand is a bit, or “binary digit”. The human brain also processes data fed to it by the sensory organs.
data bank
Database; an organized collection of data.
data bits
bits that contain information, as opposed to bits used for starting, stopping, or error checking.
data bus
A communication route through which data can travel between the computer’s central processing unit, memory, and peripherals. A 32-bit data bus can transfer 32 bits of data at one time.
data carrier
1. A medium that holds machine readable data. (tape, disk, CD, DVD, etc.)
2. A carrier frequency for data transmission.
data code
1. A coding system for abbreviating and separating data into categories such as region, class, product, etc.
2. A digital coding system for computerized data–i.e., ASCII, EBCDIC.
data communication
The transfer of data from one computer to another.
data compression
The encoding of data so it takes up less storage space. PKZIP for PC and Stuffit for Macintosh are data compression programs.
data conversion
Changing from one type of file format to another.
Data Discman
A portable drive from Sony that plays 8cm discs, originally audio CD-singles. It can play CDs in ISO 9660 format and compressed audio in CD-ROM-XA format.
data encryption
Putting data into a secret code so it is unreadable except by authorized users. (Also see encryption.)
data entry
Any process of entering data into a computer. Usually as a job description, data entry means typing information into a database program.
data error reading drive X
A DOS error message which means an area of the disk is unreadable. Sometimes, a utility program can reconstruct the damaged area.
data flow
1. The path taken by a message from origination to destination. 2. The path of data from source document to final document.
data fork
The data fork is one of two “forks” in Macintosh files. One is called the data fork and the other is called the resource fork. The data fork is simply for storing data, which is stored as as series of bytes. For example, if a text file were to be dissected, the actual text would be found in the data fork. Additional information like font size and positioning would be found in the resource fork.
Data General Corporation
A Westboro, Massachusetts computer manufacturer. Some products are the Nova minicomputers, Eclipse computers, and AViiON UNIX servers.
data interchange format
A standard file format for spreadsheet and other data structured in row and column format.
1. The physical connection between two points in a communications circuit, such as a telephone wire or a microwave beam. 2. The physical connection (such as wires) and the logical connection (protocols and programs) between points in a communications circuit. See also data link layer.
data link layer
Layer 2 of the Open Systems Interconnection (OSI) networking model, which concerns data packets and reliable data transfer. The data link layer detects and may correct errors in the physical layer.
data mining
Using computer technology to look for hidden patterns in a collection of data. For example, data mining for marketing research might reveal that customers interested in one product will also be interested in another. Data mining can be useful in scientific research, economics, criminology, and many other fields. Specialized database software has been developed for data mining.
data packet
A format in which data is transmitted over a network. A packet contains the data itself as well as addresses, error checking, and other information necessary to ensure the packet arrives intact at its intended destination.
data portability
The possibility for a set of data to be transferred from one operating system to another.
data projector
A device that projects whatever is on the computer's display onto a big screen.
data rate
The speed with which data is transfered over a circuit or a communications line between a computer and a periperal, within the computer, or within a network. It is usually measured in bits per second (bps).
data recovery
The loss of computer files can be a real crisis if no backup has been made. Corrupted data resulting from damaged disks, viruses, power spikes, and other problems can sometimes be restored. Restoration can take the form of repairing damaged disks or rescuing lost files. Norton Utilities is one popular data recovery program.
data series
In a spreadsheet, a data series is a grouping of related information, such as expenditures for each of the last 6 months. A data series can be used to create a chart which will help predict trends.
data sink
A functional unit that receives data which is transmitted.
data source name
(DSN). In a Web page that is linked to a database, or several databases, a name that is used to refer data queries, or entered data, from the Web page to the desired database, through ODBC (Open Data Base Connectivity).
data stream
A flow of data from one place to another.
Data Terminal Ready
(DTR). A signal from a communications program to a modem, which means the program is loaded and ready to run. The modem’s TR (Terminal Ready) light goes on when the modem has received this signal.
data traffic
The number of TCP/IP packets that traverse a network.
data transfer rate
(DTR). The speed at which data can be transferred. Measured in kilobytes per second for a CD-ROM drive, in bits per second for a modem, and in megabytes per second for a hard drive.
data warehouse
A very large database designed for fast processing of queries, projections, and data summaries, normally used by a large organization.
database
1. A large collection of data organized for rapid search and retrieval. 2. A program that manages data, and can be used to store, retrieve, and sort information. Examples are Lotus Approach, Microsoft Access, Filemaker, and dBASE. See also Lotus Approach
Database 2
(DB2). A relational database management system from IBM, which is available for PC, OS/2, HP, and Sun computers.
database front end
An interface which integrates database programs with other applications.
database management system
(DBMS) A complex set of programs that control the organization, storage and retrieval of data for many users; extensively used in business environments. Data is organized in fields, records and files. A database management system must also control the security of the database. Examples of database management systems are Oracle, Sybase, and Datacom.
database server
(DBS). A computer in a local area network that maintains a database and performs searches for client computers.
DATACOM
Data Communications.
datagram
A data packet carrying its own address information so it can be independently routed from its source to the destination computer.
DataTimes Corporation
An online service offering newspapers, magazines, financial information, and database services, based in Oklahoma City, Oklahoma.
datum
A fact or proposition used to draw a conclusion or make a calculation (singular of data).
daughterboard
In a personal computer, a small printed circuit board that plugs into a motherboard.
Decibel. 1. A unit that measures loudness or power, named after Alexander Graham Bell (one-tenth of a bel). 2. A unit of measurement of the loudness or intensity of sound. Audible sounds range from about 20 to 100 dB. 3. A ratio of the difference in power of two electric signals.
DB connector
A connector for a computer cable in which the plug and socket are D-shaped so they only fit together one way. DB connectors are often used for serial ports. DB-9 connectors have 9 pins and are used to connect a mouse. DB-25 connectors have 25 pins and are used to connect a printer.
DB/DC
Database/Data Communications. This term is used in describing software that has both database and communications capabilities.
DB2
Database 2. A relational database management system from IBM, which is available for PC, OS/2, HP, and Sun computers.
dBASE
A widely-used database management system, and the language used by it.
DBMS
Data Base Management System. A complex set of programs that control the organization, storage and retrieval of data for many users; extensively used in business environments. Data is organized in fields, records and files. A database management system must also control the security of the database. Examples of database management systems are Oracle, Sybase, and Datacom.
DBS
Database Server. The computer in a local area network that stores and manages the database, retrieving files for clients in the network.
DC
Direct current . An electric current flowing in one direction only.
DCA
1. Directory Client Agent. The agent used to search for names and addresses in an X.500 directory. 2. Defense Communications Agency. The government agency responsible for the Defense Data Network (DDN).
DCBS
Double-Byte Character Set. A character set which uses 16-bit (two-byte) characters rather than 8-bit (one-byte) characters. Using double-byte characters expands the possible number of combinations of 1s and 0s from 256 (as in ASCII) to 65,536 (or 256 x 256). Double-byte character sets are needed for such languages as Japanese, Chinese, and Korean, which have many characters. These character sets must be used with hardware and software that supports the double-byte format.
DCE
Digital Computing Enviroment
DCOM
Distributed Component Object Model (DCOM). An extension of COM (Component Object Model), DCOM was developed by Microsoft for Windows Operating Systems. It supports objects distributed across a network, much like IBM's DSOM protocol, which is an implementation of CORBA.
DD
Double-Density. Double-density disks have twice as much storage space per unit area than the outdated single-density format, but have less storage space than high-density disks. Double-density 3.5″ floppy disks are 720k DOS, 800k Mac, and have 2DD written on them. Double-density 5.25″ floppies have a 360k capacity.
Display Data Channel. VESA communications line between display adapter and monitor.
DDD
Direct Distance Dialing. A telephone service that allows users to dial long distance without having to call an operator.
DDE
Dynamic Data Exchange. A Windows 3 protocol that allows communication between applications so that when a document is updated in one application, related information will be updated in other documents linked to it in this way.
DDN
Defense Data Network. A network made up of MILNET and several other Department of Defense networks.
ddr
double data rate.
ddr
double data rate.
de
Top-level newsgroup category for a German newsgroup.
de facto standard
A standard which is widely used and accepted even though it is not official.
dead start
Loading and starting the system from power off; the same as a cold boot.
DeArj
A utility for decompressing archive files that have the .arj extension.
debug
To fix problems in hardware or software.
DEC
Digital Equipment Corporation. A computer manufacturer and software vendor. The Digital PDP series pioneered the minicomputer industry.
decibel
(dB). 1. A unit of measurement of the loudness or intensity of sound. 2. A ratio of the difference in power of two electric signals.
decillion
10^33 (U.S. and Canada); 10^60 (Europe).
decimal
Base 10; the numbering system in common use, in which each place to the left or right of the decimal represents a power of 10. The base 10 numbering system uses the numerals 0 to 9. The number one-hundred twenty, for example, is written 120 (1 in the hundreds place, 2 in the tens place, and 0 in the ones place). Computer languages use binary, or base 2, and hexadecimal (base 16), rather than decimal numbers.
decimal numbers
Numbers expressed in base 10, the numbering system in common use, in which each place to the left or right of the decimal represents a power of 10. Computer languages use binary, or base 2, numbers, and sometimes hexadecimal (base 16) numbers.
decimal point
( . ) ASCII character 46. Also called point; dot; period.
decimal tab
A tab setting that places the decimal point of any number at the tab stop; digits to the right and left of the decimal are aligned in place, so that the decimals are aligned vertically in a column and figures can be added or subtracted.
deckle
Ten bits.
DECmate
A word processing program.
DECnet
A network protocol from Digital Equipment Corporation, which can interconnect PDP, VAX, PC, and Macintosh computers.
decoder
Hardware or software that translates a coded signal back to its original form. Decoders are used to enable a computer to recognize instructions and addresses.
decompiler
A program that translates machine code back into a high-level source language.
decompress
To restore a compressed file to its original size.
decompression
Restoring a compressed file to its original format.
decompressor
A utility that restores a compressed file to its original size.
decrypt
To decode encrypted data.
decryption
Decoding encrypted data.
Dedicated IP Address
A static or dedicated IP Address is a type of account from an ISP where your computer(s) are assigned the same IP Address at all times. While this used to be a requirement for web-site serving, it is usually used today for security purposes.
dedicated line
A telecommunications line that lets your computer have a direct,
permanent connection to the Internet; in contrast with a dial-up connection which is only opened for temporary use. A dedicated line is assigned to only one purpose, and is always connected to the same equipment.
default
An instruction that a computer assumes, unless the user gives it other instructions. For example, if the default typeface on a word processing program is Times Roman, the user may instruct the machine to use a different default typeface; once the program is opened, a variety of types may be used, regardless of the default setting.
defect analysis
Analyzing defects, and trying to find their causes, in order to make improvements.
Defense Advanced Research Projects Agenc
(DARPA). The Federal agency that began as ARPA, and began the Internet. It became ARPA again in 1990.
Defense Communications Agency
(DCA). The government agency responsible for the Defense Data Network (DDN). Now called Defense Information Systems Agency (DISA).
Defense Data Network
(DDN). A network made up of MILNET and several other Department of Defense networks.
Defense Information Systems Agency
(DISA). The government agency responsible for the Defense Data Network (DDN). Formerly called DCA.
Defense Switched Network
(DSN). The voice, data and video communications networks of the U.S. Department of Defense, administered by the Defense Information Systems Agency (DISA); a single, integrated telephone system created from many civil and military systems, with added data communications and video teleconferencing.
definite iteration
Repeating a series of instructions for a fixed number of times; for example, performing a calculation on each item in a list.
defragment
A fragmented hard disk has parts of files stored in many different locations. To retrieve a file, the computer must search and retrieve all the fragments. Defragmenting a disk puts all the parts of each file together in one location. This reduces the time the computer spends locating files.
degauss
To demagnetize. Color monitors and the read/write heads in disk and tape drives need to be degaussed periodically to neutralize unwanted magnetism. Some monitors degauss themselves automatically when they are turned on.
degaussing
Demagnetizing; a feature of some color monitors is that they degauss themselves automatically when turned on. Color monitors and the read/write heads in disk and tape drives need to be degaussed from time to time, to neutralize unwanted magnetism.
Degrees of Freedom
(DOF). A virtual reality term used to describe motion.
Delete key. The key on the keyboard which is used to delete selected text or objects.
delete
1. To erase data from a file or remove a file from a storage medium. On the computer, deleted files are no longer visible in the directory, but the files may still be on the disk, and recently-deleted files may still be recovered through the use of software like Norton Utilities. 2. ASCII code 127, the control character entered by pressing the delete or backspace key. It erases the character immediately to the left of the cursor.
http://www.dell.com.
Delphi
An online service from News Corporation in Cambridge, Massachusetts that provides full Internet access, many databases, shopping, and electronic mail.
demand paging
A function of virtual memory in which a memory page is paged in when there is a demand for it, in other words when the program tries to access a page that is not already available in main memory.
demibold
A font style in which the characters are a weight between regular text and bold. Also called demi.
demilitarized zone firewall
A firewall architecture which employs two routers to filter and transfer information between an organization's internal network and the Internet.
demo
A free or low-priced sample of a program (often with some features disabled) that is intended to give the user enough of a taste to want to buy the program.
demonstration
1. A presentation of a product or service, showing its features and how it works, to a potential customer. 2. A preview of software (incomplete or with some features disabled) distributed for free or a low price, in order to interest users in buying the complete program.
demonstration program
A sample of a program distributed for free or a low price; the demonstration program is a partial version or has some features disabled, and is intended to entice the user to buy the complete program. A demonstration program is different from a beta version, which is a complete program distributed so users can test it and report problems.
demultiplexer
A device that separates signals that have been combined by a multiplexer for transmission over a communications channel as a single signal.
demultiplexing
The separation of signals that have been combined by a multiplexer into a single signal for transmission over a medium such as a telephone line. Demultiplexing occurs on the receiving end of the transmission.
deprecated software
Software that is considered obsolete and on its way out, usually in favor of something better. Usually, though the software may have been originally included as part of an installation, administration no longer installs the program, and slowly support for the program is phased out.
descender
The part of a character that descends below the baseline. Lowercase g, j, p, q and y have descenders; a, e, and o do not.
deselect
To cancel the selection of an item, area of text, or group of items. A mouse can be used to deselect by clicking outside the selected area, or keyboard commands can be used. When an item or area of text is deselected, it is no longer highlighted.
A professional mechanical design and drafting program, with features that expand on traditional CAD programs.
desk accessory
(DA). A small, useful program that is analogous to an item on a real office desktop, such as a clock, calculator, calendar, and message pad. Macintosh desktop accessories can be made easily available by putting them in the Apple menu. Windows desk accessories are in the Accessories group.
The whole computer screen, which represents an office desktop. With a graphical interface, the icons on the screen resemble objects that would be found on a real desktop, such as file folders, a clock, etc.
desktop case
A case for the main components of a computer system that usually sits on the desk underneath the monitor.
desktop computer
A computer that is small enough to sit on a desktop.
desktop publishing
(DTP) Using a desktop computer to produce camera-ready copy for printing. Desktop publishing makes use of word processing programs, page layout programs, and a printer. Sometimes a scanner is used for images, and draw or paint programs may be used to create artwork. Two programs used a lot in desktop publishing are PageMaker and QuarkXPress.
desktop video
(DTV). A video production made with a desktop computer and home video equipment.
The destination is the location to which a file is moved or copied.
device driver
A program that extends the operating system to support a device such as a disk or tape drive; or a program that enables an application to use a device such as a printer driver. Hardware devices such as sound cards, printers, scanners, and CD-ROM drives must each have the proper driver installed in order to run.
device handler
The component of a device driver that communicates directly with the hardware device.
device independent bitmap
(DIB ). Device independent BMP (bitmap) files are bitmapped graphic files that can be used with many different monitors and printers. An example is TIFF (Tagged Image File Format).
Dynamic Host Configuration Protocol. Windows NT Server software that assigns an IP address to each node in a network.
Dhrystone
A benchmark program that tests a variety of functions. The measure of a computer's speed in Dhrystones per second means the number of times the test program can be run in one second.
DHTML
Dynamic HTML. HTML documents with dynamic content; the three components of DHTML pages are HTML, JavaScript, and cascading style sheets. The three components are tied together with DOM, the Document Object Model.
DIA
Document Interchange Architecture. A document interchange format from IBM that allows different types of computers to exchange documents.
dial tone
An audible tone which signals that a telephone is ready to be dialed.
dial-up
A connection which uses the public telephone network. Contrast with dedicated line.
dial-up account
A type of Internet account that allows you to to dial up the Internet service provider's computer with a modem. This is a temporary connection, as opposed to a dedicated line.
Dial-Up Networking
A computer network that a user can access remotely via modem.
dialog box
A box on the computer screen that lets the user communicate with the computer. A dialog box can be used to enter information, set options, or give commands to the computer. The dialog box gives the user choices (such as open file, delete, save) which can be selected by clicking with the mouse.
DIB
1. Device Independent Bitmap. Device independent BMP (bitmap) files are bitmapped graphic files that can be used with many different monitors and printers. An example is TIFF (Tagged Image File Format). 2. Directory Information Base. An X.500 directory or online white pages.
dibit
Two bits. The possible combinations of two consecutive bits are 00, 01, 10 and 11. In phase modulation, each combination represents one of four carrier phase shifts.
DIF
Data Interchange Format. A file format for spreadsheets and relational databases.
diff
A UNIX command to display the differences between two text files.
Difference Engine
An invention conceived by British mathematician Charles Babbage in 1822. During Babbage's time, teams of mathematicians worked long hours developing trigonometry tables. The Difference Engine was a hand-crank machine that did these calculations for them, and processed the results far more accurate than the primitive calculators of the time. Babbage also created the “Analytical Engine.” See that entry for more details.
Diffie-Hellman
The first published technique for public key cryptography, based on the difficulty of calculating logs in modular arithmetic.
digerati
(Similar to "literati".) People who are experts in information technology.
digest
A mailing list option that allows a user to receive one big message instead of a lot of little ones.
digispeak
The abbreviated language used by people typing on their computers in e-mail messages, chat room conversations, and other online communication. Expressions such as IMHO (In My Humble Opinion) and CUL8R (See You Later) shorten the amount of typing that has to be done. Especially in real-time communication, abbreviating some words helps get the message across faster.
Digital Audio Tape
(DAT). A kind of magnetic tape originally designed for audio format, now also used in computers to back up data. DAT cassettes are about the size of audio cassettes, and can store up to 12GB.
Digital Automatic Music
(DAM). DAM CDs contain music in both MP3 and standard CD audio format. They can be played from an MP3 player or CD player. They often include special releases not available elsewhere.
digital camera
A camera that takes pictures without film, and records the images in digital form. The camera stores the snapshots in its memory for transfer to a computer.
digital channel
A communication channel which carries digital signals only. In order to carry voice or video signals on a digital channel, all analog signals must first be converted to digital signals before they can be carried over a digital channel. Compare analog channel.
Digital Coast
Los Angeles' competitor to Silicon Valley; a region of many high-tech companies. This is somewhat of an antiquated term.
digital computer
A computer that operates on data which is represented as binary digits (0s and 1s). All commonly-used computers are digital. See analog computer, hybrid computer.
Digital Darkroom
A Macintosh photo editing program from Silicon Beach Software, Inc.
Digital Equipment Corporation
(DEC). A computer manufacturer and software vendor. The Digital PDP series pioneered the minicomputer industry.
digital information
Information stored in binary form that a computer can understand. Text, graphics, and sound are all stored as 1s and 0s in a computer.
Digital Millennium Copyright Act
A bill which indicates United States acceptance of online copyright provisions agreed to by the World Intellectual Property Organization (WIPO).
digital pseudonym
A pseudonym an individual can use to set up an online account with an organization without revealing personal information. A public key can serve as a digital pseudonym.
Digital Semiconductor
The division of the Digital Equipment Corporation that was sold to Intel in May 1998. The Digital Semiconductor division is instrumental in developing the Alpha 64-bit processors created by the Digital Equipment Corporation.
Digital Signal Processing
(DSP). Using computers to process signals such as sound, video, and other analog signals which have been converted to digital form. Some uses of DSP are to decode modulated signals from modems, to process sound, video, and images in various ways, and to understand data from sonar, radar, and seismological readings.
digital signal processor
(DSP). A specialized CPU used for digital signal processing. Some uses of digital signal processors are with modems and sound boards.
Digital Signature Standard
(DSS). A National Institute of Standards and Technology (NIST) standard for digital signatures, used to authenticate both a message and the signer. DSS has a security level comparable to RSA (Rivest-Shamir-Adleman) cryptography, having 1,024-bit keys.
Digital Simultaneous Voice and Data
(DSVD). A digital technology for sending compressed voice and data signals at the same time over a regular telephone line.
Digital Subscriber Line
(DSL). A way of sending digital data over regular copper telephone lines. It is also called High-Speed DSL (HDSL).
digital to analog conversion
The translation of digital information (1s and 0s) into analog information, such as sound waves.
digital to analog converter
(DAC). An electronic circuit that converts digital information (for example, from a CD or CD-ROM) into analog information, such as sound and audio signals.
Digital Video Disc-Read Only Memory
(DVD-ROM). A disc like a CD-ROM that has more storage (4.7 gigabytes) and can provide digital video. DVD-ROMs with 17GB storage will soon be available.
Digital Video Interactive
(DVI). A compression/decompression technique developed by RCA, Intel, and GTE that makes it possible to store digital graphics, audio, and full-motion video on a CD-ROM, and to decompress and display these forms of data singly or in combination.
digital watermark
A watermark is a normally invisible pressure mark in expensive paper which can be seen when the paper is held up to the light. Some computer files have digital watermarks embedded in them as a pattern of bits which appear to be part of the file and are not noticeable to the user. These patterns can be used to detect unauthorized copies.
digital whiteboard
The equivalent of a blackboard, but on a computer screen. A whiteboard allows one or more users to draw on the screen while others on the network watch, and can be used for instruction the same way a blackboard is used in a classroom.
digitization
The process of translating data into digital form (binary coded files for use in computers). Scanning images, sampling sound, converting text on paper into text in computer files, all are examples of digitization.
digitizing tablet
A tablet that translates an artist's pen strokes into a computer graphic; the drawing is made on a physical tablet, which send signals into the computer to put the image on the screen.
Dimmed or grayed letters appearing on a menu mean the dimmed option is not currently available. It may mean the software for that function is not installed, or that the computer is not in the mode to use that function. Available options are shown in black.
DIMMs
Dual Inline Memory Modules. A way of adding RAM to the computer. DIMMs normally have 168 pins. See also SIMMs (Single Inline Memory Modules).
DIN connector
Deutsches Institut fur Normung (German Standards Institute) connector. A plug-and-socket connector used to connect PC keyboards and other devices. The DIN plug is an open metal cylinder with pins inside in a curved pattern. DIN plugs come in two sizes: full size, 1/2 inch diameter; mini, 5/16 inch diameter.
Ding!
An instant messaging program from Activerse, Inc.
dingbats
A group of special type characters such as hearts, squares, ornamental bullets, etc. that are used for graphic design. Two popular dingbats computer fonts are Dingbats and Wingdings.
diode
Any electronic device that restricts current flow to mainly one direction. Diodes are used to convert AC to DC.
dir
A DOS command to list the contents of a directory.
direct access
The same as random access; any area of direct access memory can be accessed directly and immediately, in contrast to, for example, a magnetic tape where the tape must be wound to the point where the data is.
Direct Access Storage Device
(DASD). A peripheral device for a mainframe computer, such as a disk or drum, that can be directly addressed.
direct current
(DC). An electric current flowing in one direction only. See alternating current.
direct distance dialing
(DDD). A telephone service that allows users to dial long distance without having to call an operator.
Direct Memory Access/Addressing
(DMA). A method of transferring data from one memory area to another without having to go through the central processing unit. Computers with DMA channels can transfer data to and from devices much more quickly. Some expansion cards can access the computer's DMA channel if the DMA channel to use is specified during installation; this is sometimes done by setting a jumper or DIP switch. See also PIO.
Direct Read After Write
(DRAW). A term that describes WO (write once) and Rewritable CD-ROMs, on which the data can be accessed immediately after being written. In the case of the original CD-ROM format, data could not be immediately read after being written; the CD had to be mass replicated first.
Direct3D
Software from Microsoft DirectX that improves 3D graphics in games; 3-D graphics programming interface from Microsoft for Windows 95 and NT that provides low-level access to the frame buffer and advanced features of the display adapter for the creation of high-speed animation.
(DIT). The directory tree representing information objects in the OSIX.500 Directory.
directory path
The identification of a file by its name and the name of all directories leading to it. Example: zoo/animals/lions. Also called pathname .
directory server agent
(DSA). The program that maintains the directory information base (DIB) in an X.500 directory; a directory client agent (DCA) is used to search for names and addresses.
directory system agent
(DSA). The program that provides the X.500 Directory Service for part of a directory information base. A DSA usually provides the directory information for one organization.
directory tree
The organization of directories (or folders) and files and on a hard drive, like the branches of an upside-down tree. The main directory is called the “root directory”.
directory user agent
(DUA). The program used by the directory user to access an X.500 Directory Service.
DISA
Defense Information Systems Agency. The government agency responsible for the Defense Data Network (DDN). Formerly called DCA.
A hyphen that will only be set if the word falls at the end of a line which is too long. The user may override the automatic hyphenation program by selecting a place for a discretionary hyphen; then if the word has to be hyphenated, it will only break in the chosen place. Discretionary hyphens are set with special keyboard commands.
Disinfectant
A downloadable virus protection program from Northwestern University.
disk cache
A section of RAM that provides a cache between the disk and the CPU. It enables the computer to operate faster. Retrieving data from hard disk can be slow; a disk caching program helps solve this problem by placing recently accessed data in the disk cache. Next time that data is needed, it may already be available in the disk cache; otherwise a time-consuming search of the hard disk is necessary. The disk cache may also be used for writing, in which case it is written to the cache at high speed and then stored until it is written to disk during idle machine cycles. See cache and memory cache.
disk formatting
Preparing a disk so a computer can read and write data on it. Formatting a disk includes creating the physical tracks and sector identification, and creating the indexes specific to the operating system it will be used on. Floppy disks can be bought preformatted or can be formatted by the user with a program on the computer.
DiskCopy
A utility used to make an exact copy of an entire floppy disk; available for DOS, Macintosh, and OS/2.
diskette
A floppy disk. A removable, portable magnetic disk on which data and programs can be stored. The older 5-1/4 inch disks are more flexible; the 3-1/2 inch disks have a hard protective case around them and are the primary size used now.
diskSpace Explorer
A disk space manager that help users allocate hard disk capacity. It features a pie chart that graphically displays disk contents; the user can navigate through files and folders just by clicking on the pie chart. The program reports the amount of space used and space wasted by files and folders. It gives an overview of how the drive’s free space might improve if it were set for a different cluster size or file system, without actually changing current settings. The program can also free additional space by compressing folders, reducing wasted space, or deleting folders no longer needed.
display
Another word for the computer screen or monitor.
display adapter
Also called graphics card, video card, or video adapter. A circuit board that enables a computer to display information on its screen. The resolution, number of colours, and refresh rate of a monitor is determined by the kind of display adapter used, plus the limitations of the monitor itself.
display font
A font with fancy letters, especially capitals; suitable for headings but too ornate for regular text.
Display PostScript
A version of PostScript used to display files on screen. The NeXT computer uses Display PostScript.
distance education
Typically a label applied to higher education classes that a student takes from home or any location other than the campus offering the program. These programs are increasingly offered via the Internet, and are designed to be accessible to the learner “anytime, anywhere.” Term often may be interchanged with “e-learning,” “online education,” “online courses.”
Distinguished Name
(DN). The authoritative name of an entry in the OSI Directory (X.500).
DIT
Directory Information Tree. The directory tree representing information objects in the OSIX.500 Directory.
DIW
Defensive Information Warfare.
DLT
Digital Linear Tape. A type of 1/2" wide magnetic tape used for backup.
DMA
Direct Memory Access/Addressing. A method of transferring data from one memory area to another without having to go through the central processing unit. Computers with DMA channels can transfer data to and from devices much more quickly than those in which the data path goes through the computer's main processor. Some expansion cards can access the computer's DMA channel if the DMA channel to use is specified during installation; this is sometimes done by setting a jumper or DIP switch. See also PIO.
DMI
Desktop Management Interface. A management system for PCs.
DMMS
Dynamic Memory Management System.
DMP
Dot Matrix Printer. A kind of impact printer that uses small closely packed needles or “pins” and an ink ribbon to make a pattern of tiny dots which form the letters on a page. Dot matrix printers are noisy and cannot print fine-quality type, but are also inexpensive and have many uses.
Distinguished Name. The authoritative name of an entry in the OSI Directory (X.500).
DNS
Domain Name System. A database system that translates an IP address into a domain name. For example, a numeric address like 232.452.120.54 can become something like xyz.com. See also Berkeley Internet Name Domain.
docking station
A piece of hardware that a portable computer can be plugged into when it is at a fixed location. The docking station makes available devices that the portable computer is not able to support, such as a battery charger, a larger screen, additional drives, or a network.
DocuComp
A program that compares two documents and finds the differences between them; from Mastersoft, Inc.
document interchange format
A file standard developed by the U.S. Navy in 1982.
Document Object Model
Is the specification of how objects in a web page are represented, and it defines the attributes associated with each object and how objects and attributes can be manipulated.
Document Style Semantics and Specificati
(DSSSL). A document tree transformation and style language (ISO/IEC 10179:1996) made to work with SGML.
document type definition
(DTD). A way of describing the structure of an XML or SGML document and how the document relates to other objects.
documentation
Instructions that come with a software program, which may include paper or electronic manuals, README files, and online help.
DOF
Degrees of Freedom. A virtual reality term used to describe motion.
DOM
is a platform- and language-neutral interface that will allow programs and scripts to dynamically access and update the content, structure and style of documents. The document can be further processed and the results of that processing can be incorporated back into the presented page
domain model
In artificial intelligence, a model for a problem area in a knowledge-based system (a computer system designed for solving problems using a knowledge base, or collection of data from human sources).
domain name
An Internet address in alphabetic form. Domain names must have
at least 2 parts: the part on the left which names the organization, and the part on the right which identifies the highest subdomain, such as the country (fr for France, uk for United Kingdom) or the type of organization (com for commercial; edu for educational, etc.). Directory levels can be indicated in other parts. The IP address is translated into the domain name by the domain name server.
domain name system
(DNS) A database system that translates an IP address into a domain name. For example, a numeric address like 232.452.120.54 can become something like xyz.com.
DOOM
A popular 3D action game created by id Software. DOOM can be played over a network or by serial link. There are shareware versions that can be downloaded.
DOS
Disk Operating System. More computers worldwide have DOS than any other operating system. There are different versions of it: PC-DOS for IBMPCs, MS-DOS for non-IBM PCs, plus Apple DOS, Amiga DOS, Novell DOS, etc.
DOS box
DOS-compatible mode. DOS applications can be run in a Windows environment by means of a DOS box, which is a virtual DOS environment.
DOSmark
A benchmark which tests the ability of a PC to run DOS applications.
dot
A period or decimal point. This terminology is used in Internet domain names; for example, .net is pronounced "dot net."
dot address
An Internet address in dot notation, like 168.446.77.22.
dot matrix printer
A kind of impact printer that uses small closely packed needles or “pins” and an ink ribbon to make a pattern of tiny dots which form the letters on a page. Dot matrix printers are noisy and cannot print fine-quality type, but are also inexpensive and have many uses.
dot notation
An Internet address indicated by numbers with dots between them, such as 124.326.99.32. This notation can be in decimal, hexadecimal, or octal, and represents a 32-bit address.
dot pitch
The distance between a dot and the closest dot of the same color (red, green or blue) on a color monitor. The smaller the dot pitch, the crisper the image. Monochrome displays do not have dots, and therefore provide a sharper image than the best color screens.
dotted quad
Another name for an IP number. The dotted quad is a unique number consisting of four parts separated by dots, like 116.245.161.2. Every machine that is on the Internet has a unique IP number, and may have one or more domain names (like “currents.net”) which are easier to remember than the number.
double precision
Using two computer words to represent a number; contrast with single precision.
double spacing
In a word processing program, a setting that gives double the normal leading between every line of text; the same as hitting two returns on a typewriter.
double-byte character set
(DCBS). A character set which uses 16-bit (two-byte) characters rather than 8-bit (one-byte) characters. Using double-byte characters expands the possible number of combinations of 1s and 0s from 256 (as in ASCII) to 65,536 (or 256 x 256). Double-byte character sets are needed for such languages as Japanese, Chinese, and Korean, which have many characters. These character sets must be used with hardware and software that supports the double-byte format.
double-click
To click the mouse button twice; used to open programs and files.
double-density
(DD). Double-density disks have twice as much storage space per unit area than the outdated single-density format, but have less storage space than high-density disks. Double-density 3.5″ floppy disks are 720k DOS, 800k Mac, and have 2DD written on them. Double-density 5.25″ floppies have a 360k capacity.
double-layer CD
A CD with two recordable layers, both on the same side. A single head adjusts the focal length of the laser to the layer being read.
double-sided disk
A floppy disk that can be recorded on both of its sides.
double-speed CD-ROM drive
(2X) A CD-ROM drive that can read information twice as fast as a music CD. At least a double speed drive is needed for multimedia CD-ROMs, and quad speed is even better.
doubly linked list
A linked list in which each data element points to both the next and previous data elements.
doughbrain
A derogatory term for a person who uses the Internet only to make money.
Dow Jones News/Retrieval Service
An online service based in Princeton, New Jersey, offering financial information, airline reservations, shopping, and other services.
down
Not operating, usually because of hardware or software problems.
down arrow
A keyboard key which has a picture on it of an arrow pointing downward; it moves the cursor down the page.
downlink
1. In satellite communications, a link from a satellite to one of its earth stations. 2. To receive data through a downlink.
download
To transfer files or data from one computer to another. To download means to receive; to upload means to transmit.
downloadable
Available for download from the Internet or another network. Many games, utilities, shareware and freeware programs, software demos, graphics, and documents can be downloaded for free; some Web sites offer downloadable items for sale by electronic funds transfer.
downloadable font
1. A font which is not built into the printer and therefore must be installed on the computer. For PostScript fonts, there is a file for the screen font and a file for the printer font; both must be installed on the computer. Fonts built into the printer are called resident fonts. 2. A font which can be downloaded from a network.
downsizing
The movement from mainframe and minicomputer systems to microcomputer networks.
downstream
1. The direction of information passed between servers. 2. Data that moves from a server to an individual computer. It is important to note that downstream differs from upstream due to their different transfer rates; for example, cable modems transfer data up to 30 Mbps downstream, but opnly 128 Kbps to 2 Mbps upstream.
downtime
The time during which a computer is nonfunctional because of problems with hardware or system software.
downward compatible
A downward compatible version of software is able to coexist with older versions that may have been installed on the machine previously, and able to read files of the older version. Also called backward compatible.
dpi
Dots per inch. A measure of the resolution of printers, scanners and monitors. The more dots per inch, the higher the resolution: 600 dpi would mean 600 x 600 = 360,000 dots per square inch.
draft quality printing
The printing mode that produces a quick low-resolution draft, good for preliminary proofing but not the best for camera-ready copy. This is the fastest way to print but produces the lowest-quality image.
drag
To move an object around on the computer screen, first point to it, press the mouse button and hold it down, and then move the mouse.
drag and drop
Moving an object on the computer screen by selecting and dragging it with the mouse, and then dropping it onto another icon, such as the trash, or a floppy disk, or an application program. In certain programs, sections of text can also be selected, dragged to another area, and dropped in.
DRAM
Dynamic Random Access Memory. A type of computer memory that is stored in capacitors on a chip and requires a refresh signal to be sent to it periodically. Most computers have DRAM chips, because they provide a lot of memory at a low cost.
DRAW
Direct Read After Write. A term that describes WO (write once) and Rewritable CD-ROMs, on which the data can be accessed immediately after being written. In the case of the original CD-ROM format, data could not be immediately read after being written; the CD had to be mass replicated first.
drawing program
A program used for drawing illustrations. Illustration programs store images in vector graphics format. Examples are Adobe Illustrator, Macromedia Freehand, and CorelDRAW. Also called draw program.
drive
A device that spins disks or tapes in order to read and write data; for example, a hard drive, floppy drive, CD-ROM drive, or tape drive.
driver
1. A device driver is a program that extends the operating system to support a device such as a disk or tape drive; or a program that enables an application to use a device such as a printer. Hardware devices such as sound cards, printers, scanners, and CD-ROM drives must each have the proper driver installed in order to run. 2. A line driver is a circuit that is used to increase the signal current in order to send data over long distances or to many circuits. It must be at each end of the transmission line.
drivers
1. Device drivers are programs that extend the operating system to support a device such as a disk or tape drive; or programs that enable an application to use a device such as a printer driver. Hardware devices such as sound cards, printers, scanners, and CD-ROM drives must each have the proper driver installed in order to run. 2. A line driver is a circuit that is used to increase the signal current in order to send data over long distances or to many circuits. It must be at each end of the transmission line.
drop cap
In typography, a very big and often ornate first letter which drops below its line of type and may take up several lines. A drop cap usually begins a chapter or section, and the regular text wraps around it.
drop carrier
To disconnect without properly logging off.
drop-down combination box
A combination box in which the list box is hidden until the user expands it (by clicking on it with the mouse or some other action).
drop-down list
A selection field which only displays one choice at first; the rest of the list is revealed when the user clicks and holds the mouse button down, or takes some other action.
drum printer
A kind of impact printer in which the full character set is on a rotating drum, and available for each printing position.
DSA
1. Directory System Agent. The program that provides the X.500 directory service for part of a directory information base. A DSA usually provides the directory information for one organization. 2. Directory Server Agent. The program that maintains the directory information base (DIB) in an X.500 directory; a directory client agent (DCA) is used to search for names and addresses.
DSDD
Double Sided/Double Density disk (720K).
DSHD
Double Sided High Density disk (1.2 meg – 1.44 meg).
DSL
Digital Subscriber Line or Digital Subscriber Loop. A technology which enables high-speed transmission of digital data over regular copper telephone lines. See also HDSL and ADSL.
DSL Access Multiplexer (DSLAM)
Digital Subscriber Line Access Multiplexer (DSLAM). A mechanism used by the phone company to link customers’ DSL connections to a single high-speed ATM line.
DSN
1. Data Source Name. In a Web page that is linked to a database, or several databases, a name that is used to refer data queries, or entered data, from the Web page to the desired database. 2. Delivery Status Notification. A MIME content-type defined by IETF that can be used by a message transfer agent (MTA) or electronic mail gateway to report the result of an attempt to deliver a message. 3. Defense Switched Network. The voice, data and video communications networks of the U.S. Department of Defense, administered by the Defense Information Systems Agency (DISA).
DSP
1. Digital Signal Processing. Using computers to process signals such as sound, video, and other analog signals which have been converted to digital form. Some uses of DSP are to decode modulated signals from modems, to process sound, video, and images in various ways, and to understand data from sonar, radar, and seismological readings. 2. Digital Signal Processor. A specialized CPU used for digital signal processing. Some uses of digital signal processors are with modems and sound boards.
DSQD
Double Sided Quad Density disk.
DSS
Digital Signature Standard. A National Institute of Standards and Technology (NIST) standard for digital signatures, used to authenticate both a message and the signer. DSS has a security level comparable to RSA (Rivest-Shamir-Adleman) cryptography, having 1,024-bit keys.
DSSS
This is the acronym for direct swequence spread spectrum, and it is used as a kind of spread spectrum radio. The signal becomes spread over many frequencies because of the DSSS.
DSSSL
Document Style Semantics and Specification Language. A document tree transformation and style language (ISO/IEC 10179:1996) made to work with SGML.
DSU/CSU
Digital Service Unit/Channel Service Unit. A way of connecting a communications line to an external digital circuit.
DSVD
Digital Simultaneous Voice and Data. A digital technology for sending compressed voice and data signals at the same time over a regular telephone line.
DTD
Document Type Definition. A way of describing the structure of an XML or SGML document and how the document relates to other objects.
DTMF
Dual Tone Modulation Frequency. The tones on a push-button telephone.
DTP
(Desktop Publishing) Using a desktop computer to produce camera-ready copy for printing. Desktop publishing makes use of word processing programs, page layout programs, and a printer. Sometimes a scanner is used for images, and draw or paint programs may be used to create artwork. Two programs used a lot in desktop publishing are Pagemaker and QuarkXPress.
DTR
1. Data Transfer Rate. The speed at which data can be transferred. Measured in kilobytes per second for a CD-ROM drive, in bits per second for a modem, and in megabytes per second for a hard drive. 2. Data Terminal Ready. A signal from a communications program to a modem, which means the program is loaded and ready to run. The modem’s TR (Terminal Ready) light goes on when the modem has received this signal.
DTS
(Digital Theater Systems). A digital home theater audio format developed by Digital Theater Systems Inc.
DTV
Desktop Video. Production of videos with a personal computer; an emerging technology.
DTVC
Desktop Video Conferencing.
DUA
Directory User Agent. The program used by the directory user to access an X.500 Directory Service.
dual band
A feature of a wireless phone that allows the handset to operate using either the 800 MHz cellular or the 1900 MHz PCS frequencies.
dual boot
A configuration that makes it possible to start a computer with one of two different operating systems.
A feature of a wireless phone that allows it to operate in both analog and digital mode.
dual tone modulation frequency
(DTMF) The tones on a push-button telephone.
dual-host gateway
A firewall architecture in which all information exchanged between the Internet and an organization's internal network must pass through the firewall.
Dublin Core
(DC). A project to create a structure for categorizing electronic documents in a similar way to the sorting of library books in a card catalogue. The Dublin Core schema has fifteen fields that give all the basic information about an electronic document, including the title, subject, creator, publisher, and date of creation. Describing documents in this way will make it possible to use search engines more effectively. See also XML, RDF, and metadata.
dumb terminal
A screen and keyboard with no intelligence of its own, which is connected a main computer, and used for simple data entry and retrieval.
dump
1. A large mass of data transferred from one place to another without any particular organization, as in wholesale backup copying of files from disk to tape. 2. A printout of the byte-by-byte contents of some part of a computer's memory, shown in hexadecimal or character form.
dumped
Involuntarily cut off from a network by carrier failure.
duodecillion
10^39 (U.S. and Canada); 10^72 (Europe).
dupe killer
A program that will protect e-mail users against mail bombs by automatically eliminating duplicate copies of e-mails.
duplex
In a communications system, the ability to simultaneously transmit and receive.
duplicate file name
A DOS error message which means that you are renaming a file to a filename that is already in use. It may also mean that the file you are renaming is being used by someone else on the network. The other user must close the file in order for you to rename it.
DVD
Digital Versatile Disc or Digital Video Disc. An optical storage medium which has greater capacity and bandwidth than a CD. DVDs can be used for multimedia and data storage. A DVD has the capacity to store a full-length film with up to 133 minutes of high quality video in MPEG-2 format, plus audio.
DVD-ROM
Digital Video Disc-Read Only Memory. A disc like a CD-ROM that has more storage (4.7 gigabytes) and can provide digital video. DVD-ROMs with 17GB storage will soon be available.
DVD+ReWritable
A DVD-based storage format similar to CD-ReWritable (CD-RW).
DVI
Digital Video Interactive. A compression/decompression technique developed by RCA, Intel, and GTE that makes it possible to store digital graphics, audio, and full-motion video on a CD-ROM, and to decompress and display these forms of data singly or in combination.
A keyboard designed to make typing more efficient, using a different arrangement of letters than the QWERTY keyboard so that the letters used most frequently are all together on the main line of keys. The problem with converting to the Dvorak keyboard is that it would require all typists to relearn how to type.
DWDM
Dense Wavelength Division Multiplexing. A process by which different colors, hence different wavelengths, of an optical signal are multiplexed onto one strand of optical fiber. Due to the unique wavelength of each signal, simultaneous transmissions of different types of signals are possible. This process has the potential of greatly increasing the capacity one optical fiber can carry.
DXF
Drawing eXchange Format.
DYM
Day Year Month
dynamic
Performed while a program is running.
Dynamic Data Exchange
(DDE). A Windows 3 protocol that allows communication between applications so that when a document is updated in one application, related information will be updated in other documents linked to it in this way.
Dynamic Host Configuration Protocol
(DHCP). Windows NT Server software that assigns an IP address to each node in a network.
dynamic HTML
(DHTML). HTML documents with dynamic content; the three components of DHTML pages are HTML, JavaScript, and cascading style sheets. The three components are tied together with DOM, the Document Object Model.
Dynamic Link Library
A plethora of information that is used by a windows application. Also, it provides specific functions through a static or dynamic link.
dynamic random access memory
(DRAM). A type of computer memory that is stored in capacitors on a chip and requires a refresh signal to be sent to it periodically. Most computers have DRAM chips, because they provide a lot of memory at a low cost.
e-business
Business conducted using electronic media such as the Internet, other computer networks, wireless transmissions, etc.
e-cash
A form of electronic funds transfer via the Internet; several systems are now being tested.
e-commerce
Electronic commerce; the use of computers and electronic communications in business transactions. E-commerce may include the use of electronic data interchange (EDI), electronic money exchange, Internet advertising, Web sites, online databases, computer networks, and point-of-sale (POS) computer systems.
e-doctor
A computer virus engineer, whose job is to provide real-time elimination of computer virus infections as soon as they appear.
e-learning
Taking a course or training via the Internet; usually the World Wide Web.
e-mail
Electronic mail. A service that sends messages on computers via local or global networks.
e-mail address
The address that gives the source or destination of an e-mail message.
e-scam
A scam, or fraud, perpetrated using electronic communications.
e-tailers
Electronic retailers; for example, retailers who do business on the Internet.
e-zine
An electronic magazine. Many ezines are online versions of print magazines.
EAD
Encoded Archival Description. An SGMLdocument type definition (DTD) for archival finding aids used by the U.S. Library of Congress and other research institutions. Archival finding aids are metadata tools such as indexes, guides, and inventories. Standardizing the format of these tools makes it easier to display them on the Internet or other networks.
EARN
European Academic Research Network. A network of universities and research labs in Europe that uses BITNET technology. It merged with RARE; the combination of EARN and RARE is called TERENA.
Easter egg
A secret message hidden somewhere in a program, that can be revealed by entering some unusual combination of commands, such as pulling down a menu while holding the command and shift keys. Computer users can stumble upon Easter eggs by accident, or hear about them through rumors. The messages can be jokes, political statements, music, or pictures; often they are credits for the developers of the software.
EasyLink
An online service from AT&T EasyLink Services in Parsippany, New Jersey that offers electronic mail, electronic data interchange, Telex, and access to databases like Knight-Ridder and CompuServe.
EATA
Enhanced AT bus Attachment.
EBC
EISA Bus Controller.
EBCDIC
Extended Binary Coded Decimal Interchange Code. An 8-bit binary code for larger IBM computers in which each byte represents one alphanumeric character or two decimal digits. Control commands are also represented. EBCDIC is similar to ASCII code, which is used on most other computers.
EBONE
European Backbone. A European network backbone service.
EC
Error Control. A modem status signal indicated by a light on the modem, which means the function that tests for errors in the transmission is active.
ECC
1. Error Check Code. 2. Error Correction Code. 3. Error Checking and Correction. Same as EDAC.
echo cancellation
Removing unwanted echoes from the signal on a telephone line.
Eckert-Mauchly Computer Corporation
The company that designed and built UNIVAC I, the first commercially successful computer. J. Presper Eckert and John Mauchly first developed ENIAC, the world's first large-scale, general-purpose digital computer, in 1946. Eckert-Mauchly was acquired by Remington Rand in 1950. UNIVAC was introduced in 1951. It filled half a garage; about 40 of the computers were sold. In 1952, UNIVAC made history by predicting the election of Dwight D. Eisenhower as U.S. President before the polls closed.
ECM
Error Correcting Memory. RAM which includes error detection and correction circuits.
ECMA
European Computer Manufacturers Association. An organization founded in 1961 by leaders of European computer companies that helped with prestandardization work for OSI. In 1994, the organization changed its name to ECMA International.
ECNE
Enterprise Certified NetWare Engineer (Novell). A Certified NetWare Engineer with additional experience in wide area networks.
Econet
A network that serves individuals and organizations working for preservation of the environment, and promotes the use of electronic networking for better communications.
ECP
1. Enhanced Capabilities Port. A high-speed enhanced parallel port from Microsoft. 2. Excessive Cross Posting. Posting the same message to many Usenet groups, including those where the subject is not relevant; also called spamming.
ECPA
Electronic Communications Privacy Act. A law which prohibits phone tapping, interception of e-mail, and other privacy violations except under special law enforcement situations usually requiring a warrant.
ECRC
European Computer-Industry Research Centre GmbH. A European research organization located in Munich, Germany, that is involved in the development of information processing technology.
ED
Extra-high Density or Extra-Density. The designation for a 3.5″ floppy disk that has a 2.88M storage capacity.
EDAC
Error Detection And Correction. Methods for detecting and correcting errors in transmitted or stored data, such as parity bits and the cyclic redundancy check.
EDC
Error Detection and Correction. Methods for detecting and correcting errors in transmitted or stored data, such as parity bits and the cyclic redundancy check.
EDGARs
Electronic Data Gathering Analysis & Retrieval system.
EDGE
Enhanced Data GSM Environment: a faster version of the GSM wireless service, EDGE is designed to deliver data at rates up to 384 Kbps, enabling the delivery of multimedia and other broadband applications to mobile phone and computer users.
EDI
Electronic Data Interchange. Conversion of a transmitted document into a format readable by the receiving computer. Also called Electronic Document Interchange.
Edison, Thomas
An American inventor (1847-1931) who made important discoveries in electric lighting, telegraphy, phonography, and photography.
edit
To make changes in a file.
EDLC
Ethernet Data Link Control. A set of rules used by computers on an Ethernet to ensure an orderly exchange of data.
EDO DRAM
Extended Data Out Dynamic Random Access Memory. A fast dynamic RAM chip that is often used with Pentium processors.
EDO RAM
Extended Data Out Random Access Memory. Same as Extended Data Out Dynamic Random Access Memory. A memory chip, used mostly with Pentium processors, that accesses data faster by overlapping cycles of data output.
EDP
(Electronic Data Processing). Data processing using electronic machines (computers).
EDTV
Extended Definition TV. Television in a wide-screen format.
edutainment
Material (such as an interactive CD-ROM) that is both educational and entertaining.
EE
Electrical Engineer.
EEC
Extended Error Correction.
EEMS
Enhanced Expanded Memory Specifications.
EEPROM
Electrically Erasable Programmable Read Only Memory. A memory chip that can be recorded or erased electrically, but that does not lose its content when electrical power is removed. It is called ROM even though it can be recorded, because it takes a lot longer to record than RAM and is only practical for recording data which is not changed often.
EFF
Electronic Frontier Foundation. A nonprofit organization established to protect public access to online resources, including freedom of expression and right to privacy. EFF is concerned with the impact of computers on society and the ethical, legal, and social issues resulting from the information revolution.
EFM
Eight to Fourteen Modulation. In magnetic media, a byte commonly has 8 bits. Optical media such as CD-ROM discs uses a 14-bit byte, a modification necessary because of the way data is stored and read with lasers, using the pits (indentations) and lands (spaces between indentations) on the disc. In transferring from magnetic to optical media, the 8-bit byte has to be modulated to a 14-bit byte. When the computer reads the CD-ROM, an interface card demodulates the 14- bit optical code back to 8-bit code.
EFTS
Electronic Funds Transfer System. A system for transferring money from one account to another via computers.
EG
Evil Grin. Also
EGA
Enhanced Graphics Adapter. A graphics adapter card that improved on the CGA (Color Graphics Adapter) and was superseded by the VGA (Video Graphics Adapter).
EGCS
Extended Graphic Character Set. A graphic character set in which each character is represented by two bytes.
EGP
Exterior Gateway Protocol. A protocol which gives TCP/IP routing information to a network's exterior gateways: the gateways (routers) that connect the network to other independent networks.
EHF
Extra High Frequency. Electromagnetic frequencies in the range of 30 to 300 gigaherz.
EIA
Electronics Industries Association. An organization which establishes Recommended Standards (RS) for hardware devices and their interfaces. RS-232 is a well-known standard for transmitting serial data by wire.
EIA-232D
Electronics Industries Association -232D. The official designation for RS-232 (Recommended Standard-232), an Electronics Industries Association standard asynchronous serial line which is used commonly for modems, computer terminals, and serial printers. See RS-232.
EIDE
Enhanced Integrated Drive Electronics. A hardware interface which is faster than IDE, allows more memory, and can connect up to four devices (such as hard drives, tape drives, and CD-ROM drives) to the computer.
Eight to Fourteen Modulation
(EFM). In magnetic media, a byte commonly has 8 bits. Optical media such as CD-ROM discs uses a 14-bit byte, a modification necessary because of the way data is stored and read with lasers, using the pits (indentations) and lands (spaces between indentations) on the disc. In transferring from magnetic to optical media, the 8-bit byte has to be modulated to a 14-bit byte. When the computer reads the CD-ROM, an interface card demodulates the 14- bit optical code back to 8-bit code.
EISA
Extended Industry Standard Architecture. A PC bus that extends the ISA bus from 16 bits to 32 bits, but can still be used to plug in ISA expansion cards.
eject button
The button that is pressed to eject a floppy disk or CD-ROM out of a drive.
ELAN
Emulated Local Area Network.
Electrically Erasable Programmable Read
(EEPROM). A memory chip that can be recorded or erased electrically, but that does not lose its content when electrical power is removed. It is called ROM even though it can be recorded, because it takes a lot longer to record than RAM and is only practical for recording data which is not changed often.
electricity
Electric current, caused by the flow of electrons, which can be used as a source of power.
electrode
A device that collects or emits electric charge and controls the movement of electrons.
electromagnetic field
(EMF). A field of force, produced by electric charges and currents, which has both an electric and a magnetic component and contains electromagnetic energy. The properties of electromagnetic fields were outlined by Scottish physicist James Clerk Maxwell in 1865.
electromagnetic radiation
(EMR). Energy in the form of waves which have both an electric and a magnetic component. Electromagnetic radiation includes radio waves, light waves, infrared, ultraviolet, X rays, etc. Computer display screens emit low-level electromagnetic radiation, which is suspected to increase the incidence of cancer, birth defects, and miscarriages. Newer displays emit reduced levels of radiation. The Swedish government established standards (called MPR) for acceptable levels of EMR in display terminals.
electromagnetic spectrum
The entire range of electromagnetic radiation; it includes frequencies of 10^23 cycles per second to 0 cycles per second, and wavelengths from 10^-13 centimeter to infinity. From the lowest frequency to the highest (or the longest wavelength to the shortest) the spectrum includes electric current, heat, radio waves, microwaves, infrared radiation, visible light (colors), ultraviolet radiation, X-rays, gamma rays, and cosmic-ray photons.
electromagnetic wave
A wave that propagates by periodic variations in electromagnetic field intensity and that is within the electromagnetic spectrum.
electromagnetism
Magnetism created by a current of electricity.
electron
A subatomic particle having a negative charge, which circles the nucleus of an atom.
electron tube
An electronic device with a sealed glass or metal container through which a controlled flow of electrons is directed through a vacuum or a gaseous medium. An electron tube containing a vacuum is called a vacuum tube; the first computers used vacuum tubes as on/off switches to indicate the 0s and 1s in digital computations.
electronic book
A book that has been converted to digital form and can be read on a computer, usually via network services or CD-ROM. Electronic books can expand on print media by adding hypertext links, search and cross-reference functions, and multimedia.
Electronic Check Project
A team organized by the Financial Services Technology Consortium (FSTC) to design protocols for E-commerce. The Electronic Check Project is responsible for Signed Document Markup Language (SDML) and the Bank Internet Payment System (BIPS).
electronic commerce
(EC) Using computer networks to conduct business, including buying and selling online, electronic funds transfer, business communications, and using computers to access business information resources.
Electronic Communications Privacy Act
(ECPA). A law which prohibits phone tapping, interception of e-mail, and other privacy violations except under special law enforcement situations usually requiring a warrant.
Electronic Data Interchange
(EDI). Conversion of a transmitted document into a format readable by the receiving computer. Also called Electronic Document Interchange.
electronic data processing
(EDP). Data processing using electronic machines (computers).
Electronic Frontier Foundation
(EFF) A nonprofit organization established to protect public access to online resources, including freedom of expression and right to privacy. EFF is concerned with the impact of computers on society and the ethical, legal, and social issues resulting from the information revolution.
electronic magazine
A publication which is in digital form. Electronic magazines can be on the World Wide Web or other online services, on floppy disk or CD-ROM, or sent by e-mail. Also called an e-zine.
electronic mail
E-mail. A service that sends messages on computers via local or global networks.
electronic mail address
The address that indicates the source or destination of an electronic mail message.
electronic mailing address
(EMA). The address for electronic mail (email ); for example, [email protected]
electronic mall
A Web site (or collection of sites) on the Internet offering products and services for sale, similar to a real-life shopping mall.
Electronic Music Management System
(EMMS). An open-architecture system developed by IBM for the preparation and distribution of all forms of digital content, including music. Some of the major publishers in the music industry support EMMS for distributing full-length, full-quality music albums to Internet users. However, EMMS requires longer downloading times than the popular MP3 format.
www.epic.org).
electronic publishing
Producing documents to be viewed on a computer screen, which may never be printed on paper. Electronically published documents may be on CD-ROM or floppy disk, or available via computer networks such as the Internet, and in addition to text and illustrations, may include video and sound clips, animated graphics, and hypertext links.
electronic serial Nnumber
(ESN). The unique number of a cellular phone that identifies it to the system for placing and receiving calls.
electronic storefront
A virtual store, usually a Web site, where products are advertised and online ordering may be available.
electronic whiteboard
The equivalent of a blackboard, but on a computer screen. A whiteboard allows one or more users to draw on the screen while others on the network watch, and can be used for instruction the same way a blackboard is used in a classroom.
electronics
A branch of physics that studies the behavior and effects of electrons, and the technology of the controlled conduction of electrons and other charge carriers.
Electronics Industries Association
(EIA) An organization which establishes Recommended Standards (RS) for hardware devices and their interfaces. RS-232 is a well-known standard for transmitting serial data by wire.
electrophotographic
Refers to the printing technique of copy machines and laser printers, in which a kind of dry ink called toner adheres to electrically charged areas of a photosensitive drum, and then is transferred to paper. The areas of the drum that are charged depend on which areas are exposed by the light source.
electrostatic
Relating to static electricity, or nonmoving electric charge.
elegant
Simple, graceful, yet effective; demonstrating the highest efficiency and economy of design. For example, in mathematics, an elegant proof; in computer programming, an elegant program.
ELF
Extremely Low Frequency. Electromagnetic frequencies below 3 kiloherz. ELF radiations from computer monitors have caused health concerns, but their effects are not definitely known. The Swedish guidelines called MPR II define acceptable levels; some monitors are designed to meet these guidelines.
elite
A typewriter type that prints 12 characters per inch (also called 12 pitch). On a computer, the closest to elite type would be 10-point Courier.
em dash
A long dash.
em space
A typographic unit of measure which is the same as the width of a capital M in a given font.
EMA
Electronic Mailing Address, or E-mail address.
EMACS
(Short for Editing MACroS). A screen editor used for writing programs on UNIX and other systems.
Emall
Similar to the traditional shopping mall, an emall is a grouping of many online vendors on one site.
embedded command
A command written within text or lines of code.
embedded hyperlink
A hyperlink that is incorporated into a line of text.
An object, such as a graphic, which has been placed in a document from another file.
embedded system
A combination of hardware and software which together form a component of a larger machine. An example of an embedded system is a microprocessor that controls an automobile engine. An embedded system is designed to run on its own without human intervention, and may be required to respond to events in real time.
EMF
Electro-Magnetic Field. A field of force, produced by electric charges and currents, which has both an electric and a magnetic component and contains electromagnetic energy. The properties of electromagnetic fields were outlined by Scottish physicist James Clerk Maxwell in 1865.
EMH
Expedited Message Handling.
EMI
Electro Magnetic Interference. Electromagnetic waves that come from electrical and electronic devices.
EMM
Expanded Memory Manager. A program to manage expanded memory.
EMMS
Electronic Music Management System. An open-architecture system developed by IBM for the preparation and distribution of all forms of digital content, including music. Some of the major publishers in the music industry support EMMS for distributing full-length, full-quality music albums to Internet users. However, EMMS requires longer downloading times than the popular MP3 format.
emoticon
A typewritten picture of a facial expression, used in e-mail and when communicating on the Internet, to indicate emotion.
emoticons
Typewritten pictures of facial expressions, used in e-mail and when communicating on the Internet, to indicate emotion. They are also called smileys :-) . See the emoticon list in this dictionary for examples.
EMP
1. Excessive Mass Posting, or Excessive Multiple Posting, on Usenet ; also called spam. 2.Electro Magnetic Pulse.
EMR
1. Electromagnetic Radiation. Energy in the form of waves which have both an electric and a magnetic component. Electromagnetic radiation includes radio waves, light waves, infrared, ultraviolet, X rays, etc. Computer display screens emit low-level electromagnetic radiation, which is suspected to increase the incidence of cancer, birth defects, and miscarriages. Newer displays emit reduced levels of radiation.The Swedish government established standards (called MPR) for acceptable levels of EMR in display terminals. 2. Enhanced Metafile Record.
EMS
Expanded Memory Specification. A way of expanding DOS Random Access Memory from one megabyte to 32 megabytes.
emulate
To pretend to be something else. A computer system or program can emulate another computer system in order to run its programs, or to make a network connection between terminals.
emulation
Emulation is said to happen when a system, or a program, performs in the same way as another system. A computer can emulate another type of computer in order to run its programs. Sometimes terminal emulation is necessary in order for one computer to make a network connection with another.
emulation mode
The operational state of a computer when it is emulating another system in order to run a foreign program.
emulator
A hardware or software device that performs like something else; for example, a printer that emulates a Hewlett Packard printer so a computer can communicate with it through a Hewlett Packard printer driver, or a Macintosh that emulates a PC so it can run PC programs. In communications, terminal emulators allow computers to connect with different kinds of networks.
en dash
A short dash, longer than a hyphen but shorter than an em dash.
en space
A typographic unit of measure which is the same as one-half the width of a capital M in a given font.
Encapsulated PostScript
(EPS). A graphics file format that can be used with many different computers and printers. EPS files can be imported into most desktop publishing software.
Encarta
A multimedia encyclopedia from Microsoft, available on CD-ROM.
encipher
To encrypt data for privacy.
Encoded Archival Description
(EAD). An SGML document type definition (DTD) for archival finding aids used by the U.S. Library of Congress and other research institutions. Archival finding aids are metadata tools such as indexes, guides, and inventories. Standardizing the format of these tools makes it easier to display them on the Internet or other networks.
encoding
1. Encryption. 2. Conversion of data into digital form; for example, converting an analog sound signal into digital data for storing on a CD.
encrypt
To encode data so that only someone with a key can read it.
encryption
Putting data into a secret code so it is unreadable except by authorized users. Also see data encryption.
end key
The key on the keyboard which, by itself or in combination with other keys, can be used to move the cursor to the next word, the end of the current line, the bottom of the screen, or the end of the document.
end system
An OSI system which can communicate through all seven layers of OSI protocols; an Internet host.
end system to intermediate system
(ES-IS). An OSI protocol for address resolution and router detection.
end-user
The person who will ultimately use a product, distinguished from all the people involved in creating or promoting it.
end-user license
A license that gives a user right to use a particular kind of software and specifies the conditions under which it may be used; for example, how many copies may be made, whether or not it may be distributed to other users, whether it can be modified by the user.
End-User License Agreement
The legal agreement between the purchaser of software and the software manufacturer. An EULA covers restricted use, terms of distribution and resale of the software.
ENDEC
ENcoder/DECoder.
endnotes
Reference notes listed at the end of a document.
Energy Star
A set of guidelines created by the U.S. Environmental Protection Agency to encourage more energy-efficient personal computers. A computer that displays the Energy Star logo automatically goes into low-power mode if several minutes elapse without anyone touching the keyboard; in this mode it uses less than 30 watts of power.
Englehart, Douglas C.
Inventor of the computer mouse, the hand-held input device commonly used with personal computers.
Enhanced Graphics Adapter
EGA. A graphics adapter card that improved on the CGA (Color Graphics Adapter) and was superseded by the VGA (Video Graphics Adapter).
Enhanced Integrated Drive Electronics
(EIDE). A hardware interface which is faster than IDE, allows more memory, and can connect up to four devices (such as hard drives, tape drives, and CD-ROM drives) to the computer.
enhancement
A change that makes a version of software or hardware better than the previous version.
ENIAC
Electronic Numerical Integrator Analyzer and Computer. The first digital electronic computer, developed by John Mauchly and J. Presper Eckert during World War II at the University of Pennsylvania and released in 1946. ENIAC was used for scientific research and weather prediction, among other things.
Enigma
An electric rotor cipher machine, invented in the 1920s, that was used to generate codes for the Germans during World War II.
ENQ
Enquiry. ASCII character 5 (control E). A request for a response, sent from one communications station to another; an enquiry as to whether someone at the receiving terminal is available to communicate.
ENSS
Exterior Nodal Switching System (Internet).
enter
The key on a numeric keypad that enters a calculation and gets the result. On some alphanumeric keyboards, the return key is called “enter.”
enterprise network
A network for a large business enterprise. This kind of network may comprise a number of local area networks which have to interface with each other as well as a central database management system and many client workstations. The design and management of an enterprise network can be very complex.
enterprise resource planning
(ERP). 1. The planning and management of all the resources in an enterprise. 2. A multi-module software system that supports enterprise resource planning. An ERP system typically includes a relational database and applications for managing purchasing, inventory, personnel, customer service, shipping, financial planning, and other important aspects of the business.
environment
The hardware/software configuration of a computer, which may refer to its human interface, networking interface, programming tools, database type, etc. The environment determines what can be done with the computer; for example, within a spreadsheet program, the computer does not respond to the commands used in a word processing program, or may respond differently.
EOA
End Of Address. A control character that indicates the end of an address, which may contain non-text characters.
EOB
End Of Block. A code indicating the end of a block of data.
EOE
End Of Extent. The end of the disk area allocated for a file.
End Of Transmission. ASCII character 4, indicating a transmission is over. 2. End Of Text. 3. End Of Tape (used on magnetic tapes).
www.epic.org).
EPLD
Electrically Programmable Logic Device.
epoch
The starting time and date from which an operating system's clock is measured. The epoch is different on different computers.
EPOP
Electronic Point of Purchase. Computerized checkout systems in stores, which may use electronic cash registers, bar code scanners, and a central computer that records transactions.
EPOW
Emergency Power Off Warning.
EPP
Enhanced Parallel Port. A high-speed transfer parallel port that can support several devices in a daisy-chain formation.
EPROM
Erasable Programmable Read Only Memory. A reusable memory chip that can be programmed electrically and erased by exposure to ultraviolet light. (Also called Electrically Programmable ROM).
EPS
Encapsulated PostScript. A graphics file format that can be used with many different computers and printers. EPS files can be imported into most desktop publishing software.
EPSF
Encapsulated PostScript File.
EQ
Equal to: = .
equalizer
A device which can boost or cut specific frequencies, to compensate for loss and distortion in signal transmission.
equals
ASCII character 61: = . The quantities on either side of the equals sign are equal to each other.
equation
A statement using an equals sign in which the expression on the left side of the equals sign is mathematically or logically equal to the expression on the right side; for example, A + B = C. Equation statements are used in programming to assign values to the variables.
ER model
(Entity Relationship Model)
ER model is a conceptual data model that views the real world as entities and relationships. A basic component of the model is the Entity-Relationship diagram which is used to visually represents data objects.Dr. Peter Chen's original paper on the Entity-Relationship model (ER model) is one of the most cited papers in the computer software field.
ER model
(Entity Relationship Model)
ER model is a conceptual data model that views the real world as entities and relationships. A basic component of the model is the Entity-Relationship diagram which is used to visually represents data objects.Dr. Peter Chen’s original paper on the Entity-Relationship model (ER model) is one of the most cited papers in the computer software field.
Erasable Programmable Read Only Memory
(EPROM). A reusable memory chip that can be programmed electrically and erased by exposure to ultraviolet light.
erasable storage
A kind of memory that can be erased and rewritten.
erase
To remove data from memory.
erase head
The device that erases magnetic tape before recording new data.
eraser
A tool in paint and photo editing programs that acts just like an eraser that is used on paper. The eraser tool is used by dragging it with the mouse.
ERCIM
European Research Consortium on Informatics and Mathematics. A group of European research organizations interested in cooperative information technology research.
ergonomics
(From Greek, “the study of work.”) The science of designing working environments and the tools in them for maximum work efficiency and maximum worker health and safety. An ergonomically designed workplace has proper light to reduce eyestrain, chairs that support good posture, lowest possible exposure of workers to undesirable radiations, etc.
ERIC
Educational Resources Information Center. An organization that provides online educational resources.
erlang
An international unit created to measure telephone use. One erlang is the equivalent of one caller talking for one hour on one telephone.
ERLL
Enhanced Run Length Limited.
EROM
Erasable Read Only Memory.
ERP
(Enterprise Resource Planning). 1. The planning and management of all the resources in an enterprise. 2. A multi-module software system that supports enterprise resource planning. An ERP system typically includes a relational database and applications for managing purchasing, inventory, personnel, customer service, shipping, financial planning, and other important aspects of the business.
ERR
Error.
error
1. A difference between a computed, observed, or measured value and the true, specified, or theoretically correct value. 2. A programming mistake which may cause a fault.
error correcting memory
(ECM). RAM which includes error detection and correction circuits.
error detection and correction
(EDAC). Methods for detecting and correcting errors in transmitted or stored data, such as parity bits and the cyclic redundancy check.
error message
A message that appears on the computer screen to let the user know the computer cannot carry out an instruction, or there is some other problem.
ES
Expert System. A computer system that is programmed to imitate the problem-solving procedures that a human expert makes. For example, in a medical system the user might enter data like the patient's symptoms, lab reports, etc., and derive from the computer a possible diagnosis. The success of an expert system depends on the quality of the data provided to the computer, and the rules the computer has been programmed with for making deductions from that data.
ES-IS
End System to Intermediate System. An OSI protocol for address resolution and router detection.
ESA
Enterprise Systems Architecture. IBM enhancements for mainframe computers to increase virtual memory and manage it effectively.
ESC
1. (Escape). ASCII character 27, the escape key. A key whose effect depends on what software or mode is being used. It is sometimes used in combination with other keys. In many programs hitting the escape key takes you out of where you are and back to where you were immediately before. 2. Execution Sequence Control.
escape key
(Esc). ASCII character 27. A key whose effect depends on what software or mode is being used. It is sometimes used in combination with other keys. In many programs hitting the escape key takes you out of where you are and back to where you were immediately before.
ESCM
Extended Services Communications Manager (IBM).
ESN
(Electronic Serial Number). The unique number of a cellular phone that identifies it to the system for placing and receiving calls.
ETB
End of Transmission Block. ASCII character 23, indicating a section of a transmission is ended.
Ethernet
The most popular type of local area network, which sends its communications through radio frequency signals carried by a coaxial cable. Each computer checks to see if another computer is transmitting and waits its turn to transmit. If two computers accidentally transmit at the same time and their messages collide, they wait and send again in turn. Software protocols used by Ethernet systems vary, but include Novell Netware and TCP/IP.
Ethernet address
The physical address of an Ethernet controller board, expressed as a 48-bit number in hexadecimal notation.
Ethernet card
A network adapter that enables a computer to connect to an Ethernet. It is a printed circuit board that is plugged into the computers on the Ethernet or may be built into their motherboards. The Ethernet cards are connected to each other by cables.
Electronic mail software from Qualcomm, Inc. for TCP/IP connections. It is available for Macintosh, OS/2, Microsoft Windows, and Windows NT.
Eudora Light
A bare bones version of the Eudora electronic mail program, distributed as freeware for PC and Macintosh.
EUnet
European UNIX Network, a major European Internet service provider.
eunet
Top-level newsgroup category for a European Usenet newsgroup.
European Academic Research Network
(EARN). A network of universities and research labs in Europe that uses BITNET technology. It merged with RARE; the combination of EARN and RARE is called TERENA.
European Backbone
(EBONE). A European network backbone service.
European Computer Manufacturers Associat
(ECMA ). An organization of computer manufacturers that helped with prestandardization work for OSI.
European Computer-Industry Research Cent
(ECRC). A European research organization located in Munich, Germany, that is involved in the development of information processing technology.
European Research Consortium on Informat
(ERCIM). A group of European research organizations interested in cooperative information technology research.
European UNIX Network
Also called EUnet; a major European Internet service provider.
A form of error checking in transmitted data in which a parity bit is 1 when there is an even number of 1 bits in the byte.
event
An occurence that is significant to a program, and which may call for a response from the program. See event-driven program.
event-driven program
A program which waits for events to occur and responds to them, instead of going through a prearranged series of actions. An example of an event would be a user clicking a mouse somewhere on the screen, or entering a keyboard command.
EVGA
Extended Video Graphics Adapter.
eWorld
A consumer and family-oriented online service from Cupertino, California.
EWOS
European Workshop for Open Systems. The OSI Implementors Workshop in Europe.
exa-
The SI prefix for quintillion (10^18). It can also mean 2^60.
exabyte
2^60 = 1,152,921,504,606,846,976 bytes; same as 1024 petabytes. The prefix exa- can also mean quintillion (10^18).
ASCII character 33: ! Also called bang, excl, and exclamation mark.
exclusive NOR
In Boolean logic, an exclusive NOR is an operation that is true if both inputs are the same.
Exclusive OR
(XOR). An exclusive OR is true if one of the inputs is true, but not both. “A XOR B” means “A or B, but not both.”
EXE
An executable binary file, marked with the .EXE filename extension in MS-DOS, Windows, OS/2, and VAX/VMS.
EXE2BIN
Program used to convert an .EXE file to binary format .COM file.
Executable
A program that a computer can directly execute.
execute
To run a program. A computer has a fetch cycle, when it is locating its next instruction, and an execute cycle, when it is carrying out the instruction.
execution
For a computer, execution is the process of carrying out an instruction given it.
executive size
A common size of paper, 7.25" x 10.5", used for stationery in the United States.
exhibition
A public showing of the latest developments in computer technology, in which different companies sponsor booths to show their products. Also called a trade show.
exit
To leave the mode or program the computer is in.
expand
To decompress a compressed file.
expanded view
A view of a computer document that shows all the text; or, a way of viewing the computer's files that shows not only the main directories or folders, but also the subdirectories/subfolders and the files within them. The opposite of collapsed view.
expansion
1. The process of returning compressed data to its original form. 2. See expansion board, expansion card, expansion slot, expansion bus, expansion unit, memory expansion.
A series of slots into which expansion cards can be plugged.
expansion card
A printed circuit board, also called an expansion board, which can be plugged into the computer's expansion slot to add a new feature; for example, a modem, higher-quality display or sound.
expansion slot
A socket on the motherboard for plugging in an expansion card. The more expansion slots a computer has, the more features can be added.
expansion unit
A unit that can be attached to the system unit of a personal computer; for example, to add storage space or processing capability.
expert system
A computer system that is programmed to imitate the problem-solving procedures that a human expert makes. For example, in a medical system the user might enter data like the patient's symptoms, lab reports, etc., and derive from the computer a possible diagnosis. The success of an expert system depends on the quality of the data provided to the computer, and the rules the computer has been programmed with for making deductions from that data.
expireware
Software with a built-in expiration time, either set for a certain date or a certain number of uses.
Explorer
The Windows 95 equivalent to File Manager in earlier Windows formats; used for exploring directories, files, and menus.
ExploreZip worm
A computer bug spread by e-mail that led to a shutdown of many corporate computer systems by infecting, damaging or destroying files. It is also called a Trojan horse because it gains entry by disguising itself as a friendly e-mail message (Hi (name inserted) I received your e-mail, and I shall reply ASAP. Till then, take a look at the zipped docs.). Users who receive such a message should delete it without clicking on the attached file, which will launch the virus and then destroy Microsoft Outlook, Express and possibly other e-mail related documents.
exponent
A superscript value written to the right of a number or mathematical expression which indicates the number of times the expression is multiplied by itself; for example, 23 is 2 x 2 x 2; 10^3 is 10 x 10 x 10. Also called a power; 2 x 2 x 2 is 2 to the 3rd power. Floating point numbers are indicated with a mantissa and a power of 10; for example, 1,400 is 14 x 10^2 ; 14,000 is 14 x 10^3.
export
To convert a file from one application format to another, or to move data out of one file with the purpose of importing it into another file.
extended ASCII
Additional ASCII characters, 128 through 255. Extended ASCII symbols may include foreign language accents, ligatures, etc. but are not always the same. For Windows, there is a standard set of extended characters 128-255 defined by ANSI.
Extended Binary Coded Decimal Interchang
(EBCDIC). An 8-bit binary code for larger IBMs in which each byte represents one alphanumeric character or two decimal digits. Control commands are also represented. EBCDIC is similar to ASCII code, which is used on most other computers.
Extended Data Out Dynamic RAM
EDO DRAM. A fast dynamic RAM chip that is often used with Pentium processors.
Extended Definition TV
(EDTV). Television in a wide-screen format.
extended graphic character set
(EGCS). A graphic character set in which each character is represented by two bytes.
Extended Graphics Array
(XGA). A super VGA card from IBM which can provide up to 1024 x 768 pixels and 65,536 colors in its images (resolutions available depend on the combination of XGA card and monitor).
Extended Industry Standard Architecture
EISA. A PC bus that extends the ISA bus from 16 bits to 32 bits, but can still be used to plug in ISA expansion cards.
Extended Technology
XT. The first IBM PC to have a hard disk. It came out in 1983. It had an Intel 8088 microprocessor, 128KB of RAM, and a 10MB hard drive.
extensible
Able to be extended or expanded. Extensible programming languages allow the programmer to customize: to add new functions and modify the behavior of existing functions.
Extensible Forms Description Language
(XFDL). An open protocol for creating, filling in, and reading complex business forms and legal contracts on the Internet and intranets. XFDL, based on XML, was developed because HTML is not suitable for representing auditable business forms. Though a form has both questions and answers, a form in HTML can only store the answers that the user entered. Using XFDL, the form’s questions and answers can be stored in a single file that can then be digitally signed.
Extensible Linking Language
(XLL). Specifications for XML linking and addressing mechanisms. XLL has been subdivided into two components: XLink and XPointer. XLink governs how links may be inserted into XML documents, whether they are simple unidirectional hyperlinks as in HTML or more sophisticated two-way, multidirectional, and typed links. XPointer defines a language to be used with XLink for addressing internal elements of XML documents.
Extensible Log Format
(XLF). A log format based on XML, designed to be extensible and universal.
eXtensible Markup Language
(XML). A new Internet language that will make the World Wide Web smarter. HTML is a markup language, consisting of text interspersed with a few basic formatting tags. XML is a metalanguage, containing a set of rules for constructing other markup languages. With XML, people can make up their own tags, which expands the amount and kinds of information that can be provided about the data held in documents. Some of the advantages are: search engines will be able to zoom in on one particular meaning of a word; new languages can be employed that will allow musical notation and mathematical and chemical symbols to be used as easily as text; e-commerce will become more practical. The World Wide Web Consortium published XML 1.0 in December 1997 (www.w3c.org/XML/).
(XSL). A language used to create stylesheets for XML, similar to CSS (Cascading Style Sheets) that are used for HTML. In XML, content and presentation are separate. XML tags do not indicate how they should be displayed. An XML document has to be formatted before it can be read, and the formatting is usually accomplished with stylesheets. Stylesheets consist of formatting rules for how particular XML tags affect the display of a document on a computer screen or a printed page. In XML, different stylesheets can be applied to the same data to hide or display different parts of a document for different users.
Extensible Virtual Toolkit
(XVT). An applications development toolkit from XVT Software, Inc., which makes it possible to develop user interfaces for multiple platforms.
extensions
In the Macintosh, drivers and other added functions (such as Dragging Enabler, Finder Help, Foreign File Access, QuickTime) which are in the Extensions folder within the System folder. The DOS equivalent is CONFIG.SYS.
exterior gateway protocol
(EGP). A protocol which gives TCP/IP routing information to a network's exterior gateways: the gateways (routers) that connect the network to other independent networks.
external drive
A drive which is outside the computer case but connected to the computer.
external interrupt
An interrupt from an external source such as the computer user, an external monitoring device, or a communication from another computer.
external modem
A modem that is outside the computer case; a separate unit that is plugged into the serial port.
external storage
Additional storage, such as floppy disk, CD-ROM, and tape storage, which is external to the computer's CPU.
external unit
A device which is outside the computer case, but connected to the computer; for example, an external modem, tape drive, or CD-ROM drive. External units are easier to detach than internal ones, and can be swapped or moved from one computer to another.
external viewer
Software external to a browser that helps the browser view files that it could not otherwise view.
extra high frequency
(EHF). Electromagnetic frequencies in the range of 30 to 300 gigaherz.
extra-density
(ED). The designation for a 3.5″ floppy disk that has a 2.88M storage capacity. Also called extra-high density
extranet
The part of a company or organization's internal computer network which is available to outside users, for example, information services for customers.
extremely low frequency
(ELF). Electromagnetic frequencies below 3 kiloherz. ELF radiations from computer monitors have caused health concerns, but their effects are not definitely known. The Swedish guidelines called MPR II define acceptable levels; some monitors are designed to meet these guidelines.
f
(femto-). One quadrillionth or 10-15.
F
(farad). A measurement of electrical charge, named after Michael Farady. One farad is the storage capacity of a capacitor having a charge of 1 coulomb on each plate and a potential difference of 1 volt between the plates.
F keys
Function keys. A set of special keys on a computer keyboard that are numbered F1, F2, etc. that perform special functions depending on the application program in use.
face change character
A control character that changes the shape and/or size of a selected area of type.
face time
Time that is spent face-to-face with someone, rather than communicating through a computer.
facsimile
(FAX). A document sent over telephone lines, originally by means of a special facsimile machine which scans a document and transmits electrical signals to print a copy of the document on the other end. Now computers can send faxes with fax software and a modem, so a fax can be sent from computer to fax machine, from fax machine to computer, or from computer to computer without requiring a printout.
factor
A quantity by which another quantity is multiplied or divided.
failure
The malfunction of a system or component; the inability of a system or component to perform its intended function. A failure may be caused by a fault.
failure-directed testing
Software testing using knowledge of the types of errors made by the system in the past that are likely to reoccur.
fall back
A modem protocol feature which allows two modems which are experiencing transmission errors to renegotiate their connection at a lower speed.
fall forward
A modem protocol feature which allows two modems which used the fall back option because of data corruption to return to a higher speed connection if the transmission improves.
fan
A cooling device that circulates air in a computer; fans are necessary to keep the computer from overheating.
fanfold paper
Continuous paper with holes on the edges, folded like a fan with each page folded the opposite direction of the page before. Fanfold paper is used in tractor-feed dot matrix printers; after printing, the pages are separated along the perforations and the edge strips are torn off.
FAP
File Access Protocol.
FAQ
Abbreviation for Frequently Asked Questions. Newsgroups, mailing lists and Internet sites often have a list of the most frequently asked questions about their subject, with answers. Newbies who have questions will find it useful to check the FAQ first. There are readily available FAQs about general use of the Internet and online services.
farad
(F). A measurement of electrical charge, named after Michael Faraday. One farad is the storage capacity of a capacitor having a charge of 1 coulomb on each plate and a potential difference of 1 volt between the plates.
FARNET
Federation of American Research Networks.A nonprofit corporation, established in 1987, dedicated to advancing the use of computer networks for research and education.
FAST
Federation Against Software Theft. A nonprofit organization in the UK, formed in 1984 by the software industry, whose aim is eliminating software piracy and educating the public about the effects of software theft.
fast packet multiplexing
A combination of fast packet technology and time-division multiplexing. Fast packet multiplexing speeds transmission by making it possible to start sending a packet before the whole packet has been received.
fast packet switching
A technology used to transmit data, voice, and images over wide area networks at high speed, by sending short packets of data. Asynchronous transfer mode is one form of fast packet switching.
fast page mode
A kind of DRAM memory. Fast page mode improved upon the original page mode memory by eliminating the column address setup time during the page cycle. For a while, fast page mode was the most widely used access method for DRAMs; it is still used on many systems. One benefit of FPM over page mode memory is reduced power consumption. See also page mode memory.
fast page mode memory
A kind of DRAM memory. Fast page mode improved upon the original page mode memory by eliminating the column address setup time during the page cycle. For a while, fast page mode was the most widely used access method for DRAMs; it is still used on many systems. One benefit of FPM over page mode memory is reduced power consumption. See also page mode memory.
fast page mode RAM
A kind of DRAM memory. Fast page mode improved upon the original page mode memory by eliminating the column address setup time during the page cycle. For a while, fast page mode was the most widely used access method for DRAMs; it is still used on many systems. One benefit of FPM over page mode memory is reduced power consumption. See also page mode memory.
Fast Wide SCSI-2
A version of SCSI (Small Computer Systems Interface) that has a 16-bit bus, a 68-pin adapter, and a maximum cable length of 9.8 feet. It can transfer data at 10-20 megabytes per second, and can be used attach a maximum of 16 devices.
FAT
File Allocation Table. A special file located in sector 0 on a disk, which contains information about the sizes of files stored on the disk and which clusters contain which files.
fat application
The version of an application that takes up the most memory. Often this is because it has specifications for many different models of computer. Selecting the version specifically for the computer it will be used on saves space.
fat binary
A program file that contains machine code for more than one type of CPU. The correct code is selected automatically according to what type of computer it is installed on. The fat binary file takes more space than a file which is specific to one type of computer, but it can be useful for switching between platforms, or for a user who is unsure which version to get.
fat client
In a client/server environment, a client that does most or all of the processing leaving little or none that must be done by the server.
fat server
In a client/server environment, a server that does most or all of the processing leaving little or none that must be done by the client.
FAT32
File Allocation Table 32. An improvement on the file allocation table (FAT) in Windows 95, the release of Windows 95 known as OSR2, and Windows 98. FAT32 raises the number of bits used to address clusters and makes each cluster smaller. FAT32 supports hard disks of up to 2 terabytes (2,048GB), which is a thousand times greater than Windows 95's previous 2GB limit. FAT32 also greatly increases the number of clusters on a logical drive, providing greater storage efficiency. Versions of Windows 95 before FAT32 have too much slack space caused by allocating a large amount of disk space to even the smallest files.
FatBits
A MacPaint tool that makes it possible to edit a graphic image one pixel at a time.
fault
An accidental condition, or a manifestation of a programming mistake, that may cause a system or component not to perform as required.
fault tolerance
The ability of a system to keep working in the event of hardware or software faults. Fault tolerance is usually achieved by duplicating key components of the system.
Favorites
A feature in Microsoft’s Internet Explorer browser that enables the user to record URLs that will be frequently used by adding them to a special menu. The equivalent in Netscape Navigator is Bookmarks. Once an URL is on the list, it is easy to return to that web page simply by clicking on the link in the list, rather than retyping the entire URL.
FAX
Facsimile. A document sent over telephone lines, originally by means of a special facsimile machine which scans a document and transmits electrical signals to print a copy of the document on the other end. Now computers can send faxes with fax software and a modem, so a fax can be sent from computer to fax machine, from fax machine to computer, or from computer to computer without requiring a printout.
fax log
A feature that can be programmed to keep copies of incoming and outgoing faxes.
FAX-out
A service that allows users of a bulletin board (BBS) who do not have fax machines to send faxes by posting them on the BBS.
fax/modem
A combination fax and data modem which is either an external unit that plugs into the serial port or an expansion board that is installed internally.A faxmodem makes it possible to fax a document straight from the computer, but cannot scan documents which are not in the computer. Most modems now are faxmodems.
FC
Font Change. A control character that changes the shape and/or size of a selected area of type.
FC/AL
Fiber Channel/Arbitrated Loop.
FCC
Federal Communications Commission. A U.S. government agency that regulates interstate and foreign communications. The FCC sets rates for communications services; determines standards for equipment; and controls broadcast licensing.
FD
1. Floppy Disk. A removable, portable magnetic disk on which data and programs can be stored. Also called diskettes, floppies are flexible plastic. The older 5-1/4 inch disks are more flexible; the 3-1/2 inch disks have a hard protective case around them and are the primary size used now. 2. Full Duplex. A communications channel which transmits data in both directions at once.
FD/HD
Floppy Disk/Hard Disk.
FDD
Floppy Disk Drive. The disk drive where a floppy disk is stored.
FDDI
Fiber Distributed Data Interface. An ANSI standard for 100 Mbit/s data transmission through fiber optic cable, in a token ring setup. Many local area networks can be linked together with a backbone that uses FDDI.
FDM
Frequency Division Multiplexing. Using several frequencies on the same channel to transmit several different streams of data, from different sources, simultaneously. A technique used for cable TV.
FDx
Full Duplex. A communications channel which transmits data in both directions at once.
feature
A property or behavior of software or hardware.
feature key
The Macintosh key with the cloverleaf (or propeller), also called the command key; equivalent to the alt key on some keyboards.
FEC
Forward Error Correction. A method of catching errors in a transmission by sending extra bits which are used on the receiving end to check the accuracy of the transmission and correct any errors.
FED
Field Emitter Display.
Federal Communications Commission
(FCC). A U.S. government agency that regulates interstate and foreign communications. The FCC sets rates for communications services; determines standards for equipment; and controls broadcast licensing.
Federal Internet Exchange
(FIX). Or Federal Internet Exchange. One of the connection points between the North American governmental internets and the Internet.
Federal Intrusion Detection Network
(FIDNET). An extensive computer monitoring system, developed by the Federal Bureau of Investigation (FBI), to protect U.S. government and private data networks from being attacked by terrorists or hostile foreign governments.
Federal Networking Council
(FNC). A group made up of representatives from DoD, NSF, NASA, etc., which coordinates networking in U.S. Federal agencies.
Federal Research Internet Coordinating C
(FRICC). The body responsible for coordinating networking among United States federal agencies, which was later replaced by the Federal Networking Council (FNC).
Federation Against Software Theft
(FAST). A nonprofit organization in the UK, formed in 1984 by the software industry, whose aim is eliminating software piracy and educating the public about the effects of software theft.
Federation of American Research Networks
(FARNET).A nonprofit corporation, established in 1987, dedicated to advancing the use of computer networks for research and education.
feedback
Return of part of a system's output to its input, so that a control device can use information about the current state of the system to determine the next control action. For example, for a thermostat to control the temperature in a room, it must continually have feedback about the current temperature in the room. Feedback is used intentionally with vacuum tube amplifiers, oscillators, etc.; an example of unintentional feedback is the high-pitched sound that results when a microphone is too close to a speaker. Feedback is also used to mean human response to a human or computer; as in interactive programs, in which the user's feedback determines what the program does.
feedback form
A form for user input. Many World Wide Web pages have electronic feedback forms.
FEFO
First Ended, First Out. A message ordering in which, among messages of the same priority level, the messages which are finished first will be transmitted first.
female connector
A socket into which a male connector is plugged.
femto-
(f). One quadrillionth or 10-15, as in femtosecond, femtojoule, femtometer.
femtosecond
One quadrillionth of a second.
FET
Field Effect Transistor. A semiconductor device used in CMOS circuits.
fetch
A computer cycle in which it locates the next instruction to execute.
Fetch
A Macintosh FTP program by Jim Matthews of Dartmouth College, in which a little dog (screen icon) runs to fetch the file for downloading.
FF
Form Feed. ASCII character 12: control-L. Feeding a form through a printer to the top of the next page. Printers that use forms often have a form feed button (FF) to push. The computer operator can signal a form feed to the printer with the control-L.
FFD
Flicker Free Display. A computer screen that has a fast enough refresh rate that no flicker can be detected; this kind of display is easier on the eyes.
FFS
Fast File System.
FFT
Fast Fourier Transform.
FHSS
This is the acronym for the word frequency-hopping spectrum. This is one of two types of spectrum radio. It is characterized by a carrier signal that hops randomly but the sequence in understood from frequency to frequency.
fiber optics
(FO). The transmission of data in the form of pulses of light. Fiber optics uses cables containing glass or silica fibers no thicker than a human hair. There is very little signal loss, and information can be transmitted at high speed over long distances. Fiber optic cables do not have problems with external noise like wire cables do, and are better for transmissions requiring security.
fiber-distributed data interface
(FDDI). ANSI standard for 100 Mbit/s data transmission through fiber optic cable, in a token ring setup. Many local area networks can be linked together with a backbone that uses FDDI.
fiber-optic cable
A cable that carries laser light, encoded with digital signals, rather than electrical energy. Made of thin fibers of glass, fiber-optic cables can transmit large amounts of data per second. Fiber-optic cables cannot be tapped by remote sensing equipment because they do not emit electromagnetic radiation.
fiber-optic connector
One of several types of devices used to join pairs of optical fibers together. Some of the types are ST connectors, SMA connectors, MIC connectors, and SC connectors.
Fibonacci series
Named after Leonardo Fibonacci, Italian mathematician; an infinite series of integers beginning 1, 1, 2, 3, 5, 8, 13, . . . in which each succeeding term is the sum of the two immediately preceding. Many formations in nature exhibit the Fibonacci series, such as pine cones and pineapples. The Fibonacci series is used in binary searches.
FIDNET
Federal Intrusion Detection Network. An extensive computer monitoring system, developed by the Federal Bureau of Investigation (FBI), to protect U.S. government and private data networks from being attacked by terrorists or hostile foreign governments.
FidoNet
A worldwide network of personal computer hobbyists which offers e-mail, discussion groups, and downloads.
Fidonews
The weekly online newsletter of FidoNet.
field
One of the items in a database record: for example, Name, City, Zip Code, etc. A field may have a specific number of characters or may vary. A group of fields make up a record.
field effect transistor
(FET). A transistor in which the current between a source terminal and a drain terminal is controlled by a variable electric field. FETs can be used to make circuits with very low power consumption.
field name
The name for a field in a database record; for example, Name, Telephone Number, Amount Due, etc.
field separator
A character, such as a comma or tab, used to separate the fields in a database record.
field squeeze
An option in a mail merge operation that deletes blank spaces in text when certain fields have no data in them.
fielded database
A database composed of data in fields, rather than a fulltext database, which is a collection of text files and documents.
FIFO
First In First Out. A method of storage in which the data stored for the longest time will be retrieved first.
fifth generation computer
The next generation of computers, beginning in the late 1990s, which will expand the use of artificial intelligence.
Fifth Generation Project
A project the Japanese government began in 1981 in the attempt to develop a new, more advanced generation of computers that could work with data in more intelligent ways and understand human languages. The project ended in 1992.
file
1. A block of information in the form of bytes, stored together on a computer or external digital storage medium, and given a name. A file may be a program, a document, a database, or some other collection of bytes. 2. To store in a file.
file allocation table
(FAT). A special file located in sector 0 on a disk, which contains information about the sizes of files stored on the disk and which clusters contain which files.
File Attach
A function that allows a file to be attached to a BBS mail message.
file compression
Compression of data in a file, in order to reduce the amount of space needed for storage or to speed up transmission of the file.
file conversion
Changing a file from one format to another. Many programs can convert files of another format that are opened within them; for example, a TeachText file can be converted into Word format simply byopening it in Word. There are conversion programs whose main purpose is to change a file from one format to another.
file extension
A notation after the end of a file's name which indicates the type of file it is. The extension follows a period; for example, LETTER.BAK (the extension “BAK” indicates this is a DOS backup file). DOS and Windows extensions must be three letters or less; Macintosh extensions can have more letters, or can be deleted.
file format
The way a file stores information.
file name
A name assigned to a file, which may be numbers, letters, or both. Some file names require extensions which give information about what kind of files they are. (Example: in the file name AUTOEXEC.BAT, .BAT is the extension.)
file not found
A DOS error message which means the computer cannot locate the file. Check the spelling of the filename or look in another directory.
file recovery program
A program that restores files that have been damaged or unintentionally deleted. Norton Utilities has a file recovery program.
file server
A computer that stores files for access by other computers.
File System Tree
The overall structure for naming, storing and organizing files in an operating system.
file transfer
Transferring a copy of a file from one computer to another.
file transfer program
A program that enables the user to copy a file from one computer to another.
file transfer protocol
(FTP). A client/server protocol for exchanging files with a host computer. Examples are Xmodem, Ymodem, Zmodem and Kermit.
file transfer, access, and management
(FTAM). The OSI remote file protocol and service. More at FTP.
file update
The addition, alteration, or deletion of data from a file.
FileMaker
A Macintosh or Windows NTdatabase program from FileMaker, Inc.(www.filemaker.com), Santa Clara, Calif. The FileMaker program was originally created by Claris. FileMaker Inc. is a subsidiary of Apple.
filename extension
A notation after the end of a file's name which indicates the type of file it is. The extension follows a period; for example, LETTER.BAK (the extension “BAK” indicates this is a DOS backup file). DOS and Windows extensions must be three letters or less; Macintosh extensions can have more letters, or can be deleted.
files
1. Blocks of information in the form of bytes, stored together on a computer or external digital storage medium, and named. A file may be a program, a document, a database, or some other collection of bytes. 2. Stores in a file.
fileserver
A computer that stores files for access by other computers.
fill pattern
In a graphics program, a solid color, screen, or other pattern used to fill a box or selected area.
fill-out form
A hypertext interface which is like a paper fill-out form, and may have fields to type into, radio buttons, and pull-down menus. Two browsers that support fill-out forms are Netscape Navigator and Microsoft Internet Explorer.
FILO
First In Last Out. A method of storage in which the data stored first will be retrieved last.
Financial Services Markup Language
(FSML). A language developed by the Financial Services Technology Consortium to control the identification and processing of electronic checks.
Financial Services Technology Consortium
(FSTC). A nonprofit organization whose membership includes banks, government agencies, universities, and high-tech businesses; FSTC is interested in developing e-commerce and making it practical. The FSTC's Electronic Check Project team created the Signed Document Markup Language (SDML) and the Bank Internet Payment System (BIPS).
find file
A utility that can be used to find files by name.
Finder
The part of the Macintosh system software that controls the desktop, including the icons, clipboard, and scrapbook. The Finder is the top level of the file hierarchy and enables the user to find and copy files. The Finder software must be in the System Folder to work.
finding aids
Tools such as indexes or guides, which can be used to find things.
Finger
A UNIX command that enables a user to find another user's login name and e-mail address, and sometimes other information; it is necessary to know the name of the computer where the other person has an account.
Finger of Death
(FOD). A wizard command in a MUD which eliminates a player, normally used only in the case of players whose behavior is impossible.
An electronic boundary that prevents unauthorized users from accessing certain files on a network; or, a computer used to maintain such a boundary.
firewall architecture
The design of a firewall. Firewalls have evolved into three standard architectures: the dual-host gateway, the screened-host firewall system, and the demilitarized zone firewall.
firewall code
The software part of a firewall; the code that prevents unauthorized users from accessing certain files on a network.
firewall machine
The hardware part of a firewall; a dedicated computer that interfaces with computers outside a network and has special security precautions built into it in order to protect sensitive files on computers within the network.
firewalls
A firewall is a hardware and/or software boundary that prevents unauthorized users from accessing restricted files on a network. The part of the network that is not behind the firewall is available to whoever logs on. There are three standard firewall architectures: the dual-host gateway, the screened-host firewall system, and the demilitarized zone firewall.
FireWire
The former name for High Performance Serial Bus. A serial bus developed by Apple Computer and Texas Instruments (IEEE 1394). The High Performance Serial Bus can connect up to 63 devices in a tree-like daisy chain configuration, and transmit data at up to 400 megabits per second. It supports plug and play and peer-to-peer communication between peripheral devices.
firmware
Software stored in ROM or PROM; essential programs that remain even when the system is turned off. Firmware is easier to change than hardware but more permanent than software stored on disk.
First Ended, First Out.
(FEFO). A message ordering in which, among messages of the same priority level, the messages which are finished first will be transmitted first.
first generation computer
One of the original computers built in the late 1940s and early 1950s, using vacuum tube technology. One of these computers filled an entire room and had many operating stations. Examples include ENIAC, the Mark 1, and the IAS computer.
first generation language
Machine language, expressed as numbers.
First In First Out
(FIFO). A method of storage in which the data stored for the longest time will be retrieved first.
First In Last Out
(FILO). A method of storage in which the data stored first will be retrieved last.
FIX
Federal Internet Exchange. One of the connection points between the North American governmental internets and the Internet.
fixed disk
A hard disk that is not removable during normal use.
fixed point
A way of storing and calculating numbers that have a fixed decimal point; for example, integers, or calculations of money amounts in which the decimal point always has two digits after it. See floating point.
fixed point number
A number in which the decimal point has a fixed position.
fixed wireless
Wireless devices or systems in a fixed location. Fixed wireless devices do not need to use satellite feeds or local phone services as mobile devices such as cell phones or PDAs use.
fixed-length field
A database field that has a fixed size; for example, a field for a telephone number that allows entry of only ten digits. A variable length field can be expanded.
fixed-pitch type
Pitch is the number of characters per inch in a given typeface. In fixed-pitch type, every character has the same width; in proportional-pitch type, some characters are wider than others.
flame
An angry message on a newsgroup or mailing list, often a personal attack instead of a remark relevant to the subject under discussion. Also, to post such a message.
flame bait
A newsgroup posting that is designed to provoke a flame war.
flame off
Words sometimes used to indicate the end of a flame.
flame on
Words sometimes introducing the beginning of a flame.
flame war
A heated argument in a newsgroup or other public electronic forum, often resulting in personal insults and other angry remarks that are off the subject.
flamer
A person who habitually flames.
flaming
Sending angry or inflammatory messages, either by e-mail or newsgroup posting. Flaming is considered bad netiquette.
Flash
(Shockwave Flash). A file format for delivering interactive vector graphics and animations over the World Wide Web.
flash memory
A small printed circuit board that holds large amounts of data in memory. Flash memory is used in PDAs and laptops because it is small and holds its data when the computer is turned off.
FlashBack
A Mac program from Aladdin that allows the user to add unlimited undos to applications. FlashBack works with virtually any program, to instantly recover files that have been damaged, erased or overwritten.
flat file database
A database used to manage a simple collection of information; for example, an address book. A flat file database is similar to a relational database, but it only has one table.
flatbed scanner
A scanner which has a flat piece of glass the document is put on to be scanned. One of the problems with a hand-held scanner is keeping the scanner steady; this problem is eliminated with a flatbed scanner because the document is stationary and a mechanically-operated scanning head moves beneath the glass. A flatbed scanner also works better than a sheet-fed scanner when the documents have cut and paste layout that might fall off.
flavor
Type, kind.
floating point
(FP). A decimal point that can be in any location. Memory locations set aside for floating point numbers can store .234, 1.23, 3.2, etc.
floating point accelerator
(FPA) Special hardware for performing mathematical calculations with floating-point numbers; the FPA may function as a coprocessor to the central processing unit. A floating-point accelerator is a larger piece of hardware than a floating-point unit, which may be on a single chip; however, both perform the same function.
floating point coprocessor
A coprocessor that assists the central processing unit by handling calculations involving floating point numbers.
floating point number
A number that can have its decimal point in any position. A memory location usable for a floating point number could store .234, 1.23, etc. Floating point numbers can be written in scientific notation; for example, 2.32E5, or 2.32 x 10^5, which is 232,000. A special floating point unit (FPU) is sometimes used to make calculations with these numbers.
floating point operations per second
(FLOPS). A unit of measurement of a computer's speed in handling floating point calculations.
floating point unit
(FPU). A coprocessor which handles operations with floating point numbers.
flood
In Internet Relay Chat, to dump a large amount of text onto a channel, thus interrupting the discussion; this is considered rude.
floppy disk
(FD). A removable, portable magnetic disk on which data and programs can be stored. Also called diskettes, floppies are flexible plastic. The older 5-1/4 inch disks are more flexible; the 3-1/2 inch disks have a hard protective case around them and are the primary size used now.
floppy disk drive
The disk drive where a floppy disk is inserted.
floppy drive
The disk drive where a floppy disk is inserted.
FLOPS
Floating Point Operations Per Second. A unit of measurement of the performance of a computer.
floptical disk
A kind of magnetic disk that uses optical technology to align the head along the tracks, by means of grooves in the disk. These disks have a much higher density than regular floppy disks, and therefore can store more data.
flow control
The control of transmission between communications devices, to make sure the sender does not send data until the receiver is ready to receive it. Flow control may be achieved by means of hardware or software. If a low-speed device is receiving a high-speed transmission, a buffer is used to store data until the receiver can accept it.
flu
Computer slang for a bad computer virus.
flush left
Alignment of text on the left margin.
flush right
Alignment of text on the right margin.
flux transition
A change of magnetic polarity.
flying mouse
A mouse that can be lifted off the desk and used as a three-dimensional pointer.
FM
Frequency Modulation. Encoding a carrier wave by modulating its frequency in accordance with an input signal.
FM synthesis
Frequency Modulation Synthesis. Synthesizing musical sounds by using one waveform to modulate the frequency of another waveform. FM synthesis is an older technique used on inexpensive sound cards, and has a tinny sound. It is being replaced by wavetable synthesis, which more closely simulates the sounds of acoustic musical instruments.
FMV
Full-Motion Video. Video that runs at the same rate at which it was filmed. Moving video images and sound available on a computer; usually stored on CD-ROM because of the large size of the files.
FNA
Free Network Address.
FNC
Federal Networking Council. A group made up of representatives from DoD, NSF, NASA, etc., which coordinates networking in U.S. Federal agencies.
FNT
Abbreviation for font.
FO
Fiber Optics. The transmission of data in the form of pulses of light. Fiber optics uses cables containing glass or silica fibers no thicker than a human hair. There is very little signal loss, and information can be transmitted at high speed over long distances. Fiber optic cables do not have problems with external noise like wire cables do, and are better for transmissions requiring security.
focus
1. A point of convergence (for example, of rays, particles, or geometrical lines); in a camera or telescope, a point of convergence of light rays that results in an image, after reflection by a mirror or refraction by a lens or optical system. 2. A point of concentration. 2. The part of a dialog box that receives input from the keyboard or mouse. 3. A window where the user can input data by means of the keyboard or mouse, also called the focus window. 4. To bring to a focus.
FOCUS
Federation on Computing in the United States. The U.S. branch of the International Federation for Information Processing (IFIP).
Focus
A database management system from Information Builders, Inc., for PCs, minicomputers, and mainframes.
focus window
In some computer systems (such as the AIX environment), a window where the user can input data by means of the keyboard or mouse.
FOD
Finger of Death. A wizard command in a MUD which eliminates a player, normally used only in the case of players whose behavior is impossible.
folder
On Macintosh and Windows 95 screens, files can be organized by placing them into folders that look like office file folders. These folders correspond to directories in DOS.
wombat.doc.ic.ac.uk/, editor Denis Howe.
followup posting
A Usenet posting which is a response to a previous posting.
font
A complete set of type characters in a particular style and size.
font cartridge
A small attachment plugged into a printer that contains ROM chips for additional fonts.
font change character
(FC). A control character that changes the shape and/or size of a selected area of type.
font editor
A program for designing fonts, or modifying existing fonts.
font family
A set of fonts of the same typeface but in different sizes and with different variations such as text, bold, italic, bold italic, demibold, etc.
font foundry
1. A place where metal is cast by melting and pouring it into molds. 2. A company where fonts are made. Originally fonts were cast in metal; now fonts are distributed as data stored in computer files.
font generator
Software that changes a scalable font into a bitmapped font, which is then stored in memory for later use. The font generator does not simply enlarge the letters, but must adjust their shapes as they get bigger.
font metrics
Font metrics for a typeface are measurements that describe the width, height, thickness, etc. for each character in a font, plus interglyph spacing, spacing of underlines, and kerning pairs.
font scaler
Software that changes a scalable font into a bitmap on the spot when needed in order to display the font onscreen or print the characters. TrueType and Adobe Type Manager are examples.
font scaling
The ability of a printer to print a font in any required size if it has instructions for the outlines of the letters.
font size
The size of the characters on the computer screen or on a printed page, usually measured in points. There are 72 points to an inch. Half-inch letters are therefore 36 points; quarter-inch letters are 18 points. Regular type in newspapers, reports, and letters is usually from 10 to 12 points; subheads are usually somewhere around 14 to 18 points; titles may be around 24 to 36 points; headlines can be 48 to 72 points or larger.
FontAgent
A Mac utility designed to repair and optimize fonts, from Insider Software.
foo
A word used on the Internet to substitute for an indefinite person, object, quantity, etc., similar to the way “X” or “John Doe” would be used. For example, “Send e-mail to [email protected]”
foo file
A temporary file. See also foo.
footer
Text that appears at the bottom of every page in a document. Footers can be set up with a template in word processing and page layout programs; the software allows the user to set up where the page numbers will be, then automatically gives a different page number for each page.
footnote
Text at the bottom of a page, which is usually preceded by a superscript number that corresponds with a number in the body of the page, and which gives additional information on the subject cited, or provides the source of the cited material. Sometimes footnotes are marked with a dagger, asterisk, or other symbol instead of with numbers.
footprint
The amount of desk space that an object takes up; a smaller computer has a smaller footprint and allows more room for other items on the desk.
force justified
Forced to justify. A line which is too long may be force justified to override automatic hyphenation or word wrapping; the type will be squeezed into one line. Normal justified text sets the last line of a paragraph flush left; therefore any line with a hard return automatically sets flush left unless force justified. For design purposes on business cards, letterheads, etc., force justifying may be used to spread out a line that is short.
force quit
A command that forces the computer to quit whatever program or operation it is running. The force quit is often used to escape from a condition in which an error has caused the computer to freeze.
foreground
The program or job in the foreground is the one the user is actively working with, and is in the foreground on the computer screen. Other processes may be running in the background at the same time; for example, the computer may be preparing a file to print.
foreground task
The task that requires the user's attention while another task runs in background. See background task.
Foreign File Access
An extension for the Apple operating system that makes it possible to read CD-Audio (ISO 9660) and CD-ROM (High Sierra Format) discs.
Foreign Key
Used in database management systems as a key which identifies records in a different table.
form feed
(FF). ASCII character 12: control-L. Feeding a form through a printer to the top of the next page. Printers that use forms often have a form feed button (FF) to push. The computer operator can signal a form feed to the printer with the control-L.
form support
The ability of a browser or server to display and process interactive forms, such as a form on a WWW page that asks for feedback from visitors.
form view
A display of one item or record out of a table, presented as a form, rather than table view which shows a number of records.
format
The organization, arrangement, and final form of a production.
format disk
To prepare a disk so a computer can read and write data on it. Formatting a disk includes creating the physical tracks and sector identification, and creating the indexes specific to the operating system it will be used on. Floppy disks can be bought preformatted or can be formatted by the user with a program on the computer.
format document
To format a document means to set the alignment, spacing, borders, header styles, fonts, and other elements that determine how the document will look.
format program
Software that erases a disk and prepares it for use.
formatted text
Text which has control codes indicating the fonts, bold or italic type, margins, indents, columns, tabs, headers and footers, and other attributes.
forms
Sections of a WWW page that can be used to interact with the Web site by entering information either through typing in text, selecting one of a number of radio buttons, selecting from a scrollable list, or clicking in a checkbox. To use forms on a Web site, a browser that supports forms is needed, such as the current version of Netscape or Internet Explorer.
forms support
The ability of a browser or server to display and process interactive forms, such as a form on a WWW page that asks for feedback from visitors.
FORmula TRANslator
(FORTRAN). The first high-level programming language for scientific and mathematical applications, developed by IBM in 1954.
FORTH
A fourth-generation programming language developed by Charles Moore in the late 1960s. The first use of FORTH was guiding the telescope at NRAO, Kitt Peak. It has also been used with games and robotics.
FORTRAN
FORmula TRANslator. A high-level programming language for scientific and mathematical applications, developed by IBM in 1954.
forum
A discussion group on a particular subject that is hosted by a BBS, a newsgroup, or a mailing list, or another online service.
forward analysis
A way of analyzing which makes it possible to determine certain properties of the output of a program by knowing the properties of the input.
forward compatible
Describes software that is compatible with later versions of the same program. Also called upward compatible.
Forward Error Correction
(FEC). A method of catching errors in a transmission by sending extra bits which are used on the receiving end to check the accuracy of the transmission and correct any errors.
FOSSIL
Fido Opus Seadog Standard Interface Layer.
foundry
1. A place where metal is cast by melting and pouring it into molds. 2. A semiconductor manufacturing plant that makes chips for other companies. 3. A company where fonts are made (font foundry).
Fountain
A virtual reality modeling language (VRML) viewer for Windows.
Four-color printing
Printing in full color, accomplished with four color separations: cyan, magenta, yellow and black (CMYK).
fourth-generation computer
A computer built using large-scale integration (integrated circuits that contain more than 100 logic gates) or very large-scale integration (integrated circuits containing 10,000 or more logic gates). Microcomputers are fourth-generation computers.
fourth-generation language
A language that is more advanced than third-generation language, in which the commands are closer to regular spoken language. Fourth-generation languages were written to streamline operations formerly done with third-generation languages, such as database queries.
FOV
Field Of View. A term used in virtual reality.
Fox Software
The software company that developed FoxBASE+ and FoxPRO.
FP
Floating Point. A decimal point that can be in any location. Memory locations set aside for floating point numbers can store .234, 1.23, 3.2, etc.
FPA
Floating Point Accelerator. Special hardware for performing mathematical calculations with floating point numbers; the FPA may function as a coprocessor to the central processing unit. A floating-point accelerator is a larger piece of hardware than a floating-point unit, which may be on a single chip; however, both perform the same function.
FPLA
Field Programmable Logic Array.
FPM
Fast Page Mode. A kind of DRAM memory. Fast page mode improved upon the original page mode memory by eliminating the column address setup time during the page cycle. For a while, fast page mode was the most widely used access method for DRAMs; it is still used on many systems. One benefit of FPM over page mode memory is reduced power consumption. See also page mode memory.
FPS
Frames Per Second. A unit used to measure computer and display performance. A frame is one complete scan of the display screen. Each frame consists of a number of horizontal scan lines; each scan line includes a number of pixels on the computer screen. The number of horizontal scan lines represents the vertical resolution and the number of pixels per scan line represents the horizontal resolution of the display. The refresh rate, or the number of times the displayed image is refreshed per second, is measured in frames per second.
fps
Frames per second. A measurement of the speed at which pictures (frames) are displayed in sequence in a film or video. The more frames displayed per second, the smoother the motion appears. Full-motion video uses 30 fps or more.
FPT
Forced Perfect Termination.
FPU
Floating Point Unit. A coprocessor which handles operations with floating point numbers.
FQDN
Fully Qualified Domain Name. The full name of a system, containing its hostname and its domain name.
FRAD
Frame Relay Access Device. A combination of hardware and software that is used to convert communications packets from formats like TCP, SNA, IPX, and others into frames that can then be sent over a frame relay network.
fragment
In network communications, a piece of a packet. Sometimes a communications packet being sent over a network has to be temporarily broken into fragments; the packet is reassembled when it reaches its destination.
fragmentation
The storage of a file on a disk in fragments which are not next to each other. When a file is stored, the data is placed in whatever disk areas are available, which may mean breaking it into fragments. Defragmenting puts all the fragments of each file together and the areas of free space together, thus speeding up access time and making more free space available on the disk.
FRAM
Ferroelectric Random Access Memory. Non-volatile semiconductor memory good for 10 years.
frame
1. A variable-length packet of data that is transmitted in frame relay technology. 2. One complete scan of the computer display screen. 3. In video or film, a single picture of a series that, displayed in sequence, creates the illusion of motion. 4. In computer graphics, the boundary that surrounds a graphic image. 5. On World Wide Web pages, a bordered area that acts as an independent browser window.
frame grabber
A board that can be plugged into the computer which makes it possible to capture single frames from a video and digitize them.
frame rate
The rate at which frames, the individual pictures that in sequence create the illusion of motion, are displayed in a film or video. Frame rate is measured in frames per second (fps).
frame relay
A protocol for sending small packets of data over a network. Frame relay uses packets of variable length, unlike cell relay, and requires less stringent error detection than other forms of packet switching because it is designed to take advantage of the more reliable circuits that have become available in recent years. Frame relay is often used for wide area networks, where it can transmit data at high speed more efficiently than point-to-point services. Frame relay is used with digital lines.
frame relay access device
(FRAD). A combination of hardware and software that is used to convert communications packets from formats like TCP, SNA, IPX, and others into frames that can then be sent over a frame relay network.
Frame Technology Corporation
Developers of FrameMaker desktop publishing program. Frame Technology later was taken over by Adobe.
FrameMaker
A desktop publishing program developed by Frame Technology Corporation, available for UNIX, Macintosh and Windows.
frames
On World Wide Web pages, a frame is a bordered area that acts as an independent browser window. There can be a number of frames within the same page, and they can be separately scrolled, linked, and viewed. Sometimes a frame can be used to view an entirely different website without leaving the original site that contains the frame. To view a page that has frames, one must use a WWW browser that supports frames, such as the current versions of Netscape and Internet Explorer.
frames per second
(fps). A measurement of the speed at which pictures (frames) are displayed in sequence in a film or video. The more frames displayed per second, the smoother the motion appears. Full-motion video uses 30 fps or more.
free software
Software that is free from licensing fees and has no restrictions on use; it can be freely copied, redistributed, or modified.
Free Software Foundation
(FSF). A nonprofit organization which promotes the development of free software. The GNU project is one of the best-known activities of the Free Software Foundation.
free space
Empty space on a hard drive, available for loading programs or data. The description of a program for a new user normally indicates the amount of free space needed to load the program. A program that calls for 4 megabytes of free space will take up 4 megabytes on the hard drive.
free speech online
A movement promoted by the Electronic Frontier Foundation and other organizations to protect the right to freedom of expression in network communications, and specifically to protest the Communications Decency Act and similar legislation. Some WWW pages have icons on them supporting free speech online.
free storage
Available storage.
free Web page
(FWP). There are some World Wide Web sites that offer free Web pages to the general public or a selected group of users. There are other sites that offer a free Web page along with membership.
Freenet
A community-based bulletin board system which is part of the National Public Telecomputing Network (NPTN), a Cleveland, Ohio, organization whose aim is to make computer networking as available as public libraries. Freenets are operated by volunteers and funded by donations.
freenet
An organization that provides Internet access to the public for free or for a small contribution.
Freeserve
A popular UK Internet service provider which has no monthly subscription fee, relying instead on call revenue plus premium rate income for calls to its telephone support lines.
freeware
Freeware is software that is available free of charge, but which is copyrighted by the developer, who retains the right to control its redistribution and to sell it in the future. Freeware is different from free software, which has no restrictions on use, modification, or redistribution.
freeze
The condition of a computer when the pointer and everything on the screen is frozen in place, and the computer does not respond to commands; one kind of crash.
frequency
The number of repetitions per unit time of a complete waveform, from peak to trough; for example, the rate of signal oscillation in sound waves or electric current. Frequencies are measured in cycles per second, or Hertz.
frequency division multiplexing
(FDM). Using several frequencies on the same channel to transmit several different streams of data, from different sources, simultaneously. A technique used for cable TV.
frequency modulation
(FM). Encoding a carrier wave by modulating its frequency in accordance with an input signal.
frequency modulation synthesis
FM synthesis. Synthesizing musical sounds by using one waveform to modulate the frequency of another waveform. FM synthesis is an older technique used on inexpensive sound cards, and has a tinny sound. It is being replaced by wavetable synthesis, which more closely simulates the sounds of acoustic musical instruments.
Frequency Shift Keying
(FSK). Frequency modulation of a carrier signal by a digital signal, in which changes in frequency represent 0s and 1s.
FRICC
Federal Research Internet Coordinating Committee. The body responsible for coordinating networking among United States federal agencies, which was later replaced by the Federal Networking Council (FNC).
FRICC
Federal Research Internet Coordinating Committee. A committee founded to coordinate networking in U.S. Federal agencies. The forerunner of the FNC.
friction feed
A method of using rollers or some other device to pass ordinary paper through a printer, unlike the tractor feed method which requires paper with holes at the sides.
friendly name
An easily-used and natural language name for something that may have a more technical designation. For example, a modem on a network could be called z2x/144 or a more friendly name like Modem2.
frisbee
Computer slang for a CD-ROM.
fritterware
Software that gives a user more options and capabilities than are really needed for practical purposes. The user fritters away the time trying all the options and fiddling around with it.
front end
A small computer through which a user communicates with a larger computer; or, a program that provides a user-friendly interface to another, harder-to-use, program.
FrontPage Extension
Server-side extensions for Web servers which allow the processing of Microsoft FrontPage scripting tags.
frowney
A frowning face :-( (emoticon).
frozen
1. The condition of a computer when the pointer and object on the screen do not move, and the computer does not respond to commands; one kind of crash. 2. No longer being updated; for instance, a software version that is no longer being improved, but is kept available for use on older systems that can not use the newer version.
fry
To send too much electrical current through a computer or component, resulting in damage.
fry the screen
To send a flame message.
fsb
Front Side Cache
fsb
Front Side Cache
FSF
Free Software Foundation. A nonprofit organization which promotes the development of free software.
FSK
Frequency Shift Keying. Frequency modulation of a carrier signal by a digital signal, in which changes in frequency represent 0s and 1s.
FSML
Financial Services Markup Language. A language developed by the Financial Services Technology Consortium to control the identification and processing of electronic checks.
FSN
Full-Service Network. A video network that makes it possible for the television to work like a computer, through the use of special equipment; users have access to video, home shopping, interactive games, and other services.
FSTC
Financial Services Technology Consortium. A nonprofit organization whose membership includes banks, government agencies, universities, and high-tech businesses; FSTC is interested in developing E-commerce and making it practical. The FSTC's Electronic Check Project team created the Signed Document Markup Language (SDML) and the Bank Internet Payment System (BIPS).
FT3
Same as T3 line. A connection made up of 28 T1 carriers, used to transmit digital signals on fiber-optic cable at 44.736 megabits per second. T3 can handle 672 voice conversations or one video channel.
FTAM
1. File Transfer and Access Method. A way of transferring files between dissimilar systems. 2. File Transfer, Access, and Management. The OSI remote file protocol and service.
FTM
Flat Tension Mask (Zenith).
FTP
File Transfer Protocol. A client/server protocol for exchanging files with a host computer. Examples are Xmodem, Ymodem, Zmodem and Kermit.
FTP by mail
A service offered by DEC which makes it possible for people without Internet access to get copies of files available by anonymous FTP, by sending a message with just the word “help” in the body to .
FTP Explorer
An FTP client that has an interface based on Windows 95’s File Manager.
FTP site
An Internet site where users can upload or download files.
Fujitsu
A Japanese elecronics corporation.
full featured
Having all available features; the most advanced version (of hardware or software).
full path
A designation of the location of a file which includes the root directory and the descending series of subdirectories leading to the end file.
full-adder
The arithmetic and logic unit of a computer performs binary addition by means of logic circuits called half-adders and full-adders. A half-adder adds one-digit binary numbers; a full-adder handles larger binary numbers in combination with a half-adder, and can carry over numbers. For larger numbers, more full-adders are used – one for each digit in the binary numbers added.
full-duplex
A communications channel which transmits data in both directions at once.
full-motion full-screen video
Video that fills the full display screen and shows lifelike smooth motion, instead of the video on some CD-ROMs and Internet downloads which is in a tiny window and only shows jerky movement. Full-motion, full-screen video is made possible by compression programs such as MPEG, which make video files small enough to transfer to the computer at high speed.
full-motion video
(FMV) Video that runs at the same rate at which it was filmed. Moving video images and sound available on a computer; usually stored on CD-ROM because of the large size of the files.
full-service network
(FSN). A video network that makes it possible for the television to work like a computer, through the use of special equipment; users have access to video, home shopping, interactive games, and other services.
full-text database
A large collection of text files or documents, which are indexed and searchable. Also called a textbase.
fully qualified domain name
(FQDN). The full name of a system, containing its hostname and its domain name.
fully qualified name
A qualified name that specifies all classifying names in the hierarchical sequence that fully defines it.
function keys
A set of special keys on a computer keyboard that are numbered F1, F2, etc. that perform special functions depending on the application program in use. Also called F keys.
functional unit
One of the units within the CPU that has a specific job to do, such as the arithmetic and logic unit.
fusing
The permanent bonding of toner to a printed page, accomplished in the fusing system of a printer or photocopier by use of heat and pressure.
fuzzy computer
A computer that is designed to use fuzzy logic.
fuzzy logic
A formal system of logic in which numbers on a scale from 0 to 1 are used instead of the values “true” and “false” as absolutes, to accurately represent the fact that some questions do not have a simple yes or no answer. Fuzzy logic was developed by Lofti Zadeh of the University of California, Berkeley.
fuzzy search
A type of search that returns not only exact matches, but also answers that are close. A fuzzy search can be useful when the user is not sure of the spelling, or wants to find information about a broad subject area.
FWP
Free Web Page. There are some World Wide Web sites that offer free web pages to the general public or a selected group of users. There are other sites that offer a free web page along with membership.
G
1. Giga – one billion. 2. Grin, or Giggle (chat).
G/L
General Ledger. Part of an accounting program.
G3
Apple's name for the PowerPC 750 chip.
Galileo
A benchmark that tests a computer's I/O subsystem performance under a controlled load. Later renamed IOmeter.
game pad
A device that allows the user to control every facet of a game via the buttons and mini-joystick on the device. Game pads are much more intuitive and easier to use than a mouse or keyboard.
game port
A socket where a joystick can be attached for gaming.
games network
A network of personal computers linked so the users can play games with each other.
gaming
Playing games. Games played on computers include MUDs, RPGs, 3-D simulation games, etc.
gamut
The range of colors a monitor can display.
gated
1. Capable of being switched on and off. 2. Switched on.
GateD
Gateway Daemon. Software that supports multiple routing protocols from the GateDaemon Consortium at Cornell University.
Gatekeeper
A set of Macintosh system extensions and control panels which offer protection against viruses. Created by Chris Johnson, Gatekeeper monitors computer activities for suspicious events in an attempt to intercept what could be variants of known viruses or completely new viruses.
Gates, Bill
William Henry Gates III, co-founder of Microsoft in 1975 with Paul Allen.
gateway
A device that connects two computer networks that use different protocols. It translates between protocols so that computers on the connected networks can exchange data. For example, commercial online services often have gateways for sending e-mail to Internet addresses.
Gateway 2000
A company in N. Sioux City, South Dakota, that manufactures PCs and sells many products by mail order.
Gateway Daemon
GateD. Software that supports multiple routing protocols from the GateDaemon Consortium at Cornell University.
Gauss
A unit of measurement of the strength of a magnetic field; one gauss = 1 Maxwell / cm^2.
Gauss, Carl Friedrich
Carl Friedrich Gauss, a German mathematician (1777-1855). He discovered the method of least squares, Gaussian elimination, Gaussian primes, and Gaussian distribution, and made many other contributions to mathematics. The Gauss, a unit of measurement of electromagnetism, was named after him.
Gaussian distribution
Normal distribution; the frequency distribution of many natural phenomena, which can be graphed as a bell-shaped curve.
Gaussian noise
Interference generated by the movement of electricity in a communications line. Also called white noise.
Gb
Giga bit. 1,024 megabits or 1 billion information bits.
GB
Giga Byte. 1,024 megabytes or 1 billion characters of information.
Gbit
Gigabit. One billion bits.
Gbps
Gigabits per second (billion bits per second).
Gbyte
Gigabyte; one billion bytes.
GDI
Graphical Device Interface, Graphics Device Interface, or Graphics Display Interface. The system by which graphics are displayed in Microsoft Windows. The application in use sends GDI the parameters for the image to be represented. GDI produces the image by sending commands to the monitor, printer, or other output device. Newer versions of Windows also have the DirectDraw interface, adding a faster mechanism for displaying games, full-motion video and 3-D objects. When the CPU is not busy, GDI updates the video display. When the CPU is busy, DirectDraw allows the application to communicate directly with the video adapter.
GE
Greater than or equal to: >= .
Gecko
The layout engine for Netscape Navigator and Communicator 5.0; the part of the browser that reads Web pages and displays graphics and text as indicated by the markup language. Because of its streamlined code, Gecko can load Web pages up to 10 times faster than Communicator 4.5, and uses much less memory. Low memory requirements make it useful for devices like wireless phones and pagers. Gecko supports HTML 4.0, Cascading Style Sheets Level 1 (CSS1), Document Object Model (DOM), Resource Description Framework (RDF), HTTP 1.1, and XML. It can be used across a wide range of platforms and devices. Gecko was developed after Netscape released its browser engine source code as part of the Open Source initiative. Netscape offers the Gecko end user license for free.
GEDCOM
GEnealogical Data COMmunication. A common file format used to exchange computerized genealogical data between different genealogy programs.
GedML
(GEDCOM Genealogical Data in XML). A method of encoding genealogical data which combines Genealogical Data Communication (GEDCOM) and Extensible Markup Language (XML).
geek
A person who, for one reason or another, is considered socially unacceptable by the person speaking. A computer geek is someone who is socially inept but expert with computers. As computers become more important in the average person’s life, this term becomes more often a compliment than an insult.
GEM
Graphics Environment Manager (Digital Research Inc.).
gender mender
A coupler with two male ends used to connect two female connectors, or a coupler with two female ends used to connect two male connectors.
GEnealogical Data COMmunication
(GEDCOM). A common file format used to exchange computerized genealogical data between different genealogy programs.
General Electric Network for Information
(GEnie Services). An online service from GE Information Services, with news, sports, business, computer technical support, games, software downloads, reference services, chat, bulletin boards, e-mail, and fax.
General Image Manipulation Program
(GIMP). Also called GNU Image Manipulation Program. Freely distributed software for photo retouching, image composition, and image authoring. This program for UNIX and X was written by Peter Mattis, Josh MacDonald, and Spencer Kimball, and released under the GNU General Public License (GPL).
General MIDI Standard
(GMS). A standard designation of specific instruments to specific < a href="/resources/dictionary/secondary_definition.php?lookup=3696">MIDI patch locations, so that a composition produced on one system will sound the same when played on another (notes originally assigned to trumpets will still be played by trumpets, etc.). GMS has 128 different sounds.
general packet radio service
(GPRS). A global system for mobile communications (GSM) channel aggregation system that increases per-channel speeds from 9,600 to 14,400 bits per second (bps), adding data compression. With GPRS, mobile data transmissions can be as fast as 115,000 bps using the existing GSM base station infrastructure. GPRS technology works well with services such as wireless Internet, wireless intranet, and multimedia. One of the main benefits of this technology is that users are, in effect, always connected, and yet are only charged for the amount of data actually transmitted.
General Public License
(GPL). A license applied to software from the Free Software Foundation and the GNU project, which guarantees users the freedom to share the software and make changes in it.
general-purpose computer
A computer that can be programmed to do many different kinds of tasks, rather than one that is limited by design to a specific task. Most computers are general purpose, and can have software installed for many different uses. A customized chip, called an application-specific integrated circuit (ASIC), can be used to create a special-purpose computer.
generalized markup language
(GML). A language that can be used to identify the different parts of a document in a general way, which can be interpreted by different processing systems to make possible different presentations of the same information.
generic markup
A method of marking up a document to indicate its logical components, such as paragraphs, headers or footnotes. SGML and HTML are examples. Generic markup does not give specific layout instructions. For example, an indication for an H1 heading does not specify whether H1 headings throughout will be bold, italic, 24-point, 18-point, etc.
GEnie Services
General Electric Network for Information Exchange. An online service from GE Information Services, with news, sports, business, computer technical support, games, software downloads, reference services, chat, bulletin boards, email, and fax.
Geographic Information System
(GIS). A computer system that has maps and geographic information, and sometimes analyses of geographic data. Geographic information systems have many uses including government, tourist information, education, environmental information, engineering, marketing.
GEOS
1. Graphic Environment Operating System (Geoworks). 2. Geostationary satellite. A satellite that always remains over a specific point on the surface of the Earth, traveling through space as the Earth orbits.
geostationary satellite
(GEOS). A satellite that always remains over a specific point on the surface of the Earth, traveling through space as the Earth orbits. A satellite dish is used to receive its communications. Using three geostationary satellites, it is possible to send a signal all over the Earth.
get
An FTP command to copy a file from the remote computer to the local computer.
Get Info
A window that provides information about a selected file. Get Info tells whether a file is a document or application, the size of the file, where it is on the computer, and whether it is locked. For a document file, Get Info tells when it was created, the last date it was edited, and what application it is in. For an application file, Get Info tells what company the application is from, and what version it is. A box is provided for comments added by the user.
GFLOPS
GigaFLOPS. One billion floating point operations per second.
GGP
Gateway-gateway protocol (on the Internet).
ghosting
When an image is dragged across a computer screen, a lingering shadow of the image where it was before. Ghosting only happens on inexpensive portable computer screens.
Ghostscript
An onscreen viewer for Postscript (.ps) files, available for Mac, Windows, and UNIX.
GHz
Giga Hertz. A billion Hertz.
Gibson, William
The author of what is considered the first cyberpunk novel, Neuromancer, in 1984, and of other similar novels.
GIF
Graphics Interchange Format. A format used for displaying bitmap images on World Wide Web pages, usually called a "gif" because .gif is the filename extension. These files use lossless compression and can have 256 colors. JPEG and GIF are commonly used for images on the Web; JPEG is considered best for photos and GIF for other graphic images.
GIF Converter
A Mac shareware utility that can be used to view and modify GIF files.
GIF89
GIF89 is a form of GIF in which one of the colors can be made transparent. The transparent area of the file lets the background color of the page it is on show through.
giga-
A prefix meaning one billion (10^9) or 1,073,741,824 (2^30).
gigabit
One billion bits. Abbreviated Gb, Gbit and G-bit.
Gigabit Ethernet
A standard for a high-speed Ethernet, approved by the IEEE (Institute of Electrical and Electronics Engineers) 802.3z standards committee in 1996. It supports the extension of existing Ethernet and Fast Ethernet standards, providing increased network bandwidth and interoperability among Ethernets at operating speeds from 10 Mbps to 1000 Mbps. Gigabit Ethernet can be used in backbone environments to interconnect multiple lower speed (10 and 100 Mbps) Ethernets. Its tenfold increase in bandwidth will benefit high performance file servers. It uses the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) protocol of the original Ethernet standard.
Gigabit Ethernet Alliance
An alliance formed by industry leaders 3Com, Bay Networks, Cisco, Compaq, Granite Systems, Intel, LSI Logic, Packet Engines, Sun Microsystems, UB Networks, and VLSI Technology, to support a multi-vendor effort to provide customers with open, cost-effective and interoperable Gigabit (1000 megabits per second) Ethernet products. Technical proposals were submitted to the IEEE (Institute of Electrical and Electronics Engineers) 802.3z standards committee, and approved in 1996. The objective of the Gigabit Ethernet Alliance is to support the extension of Ethernet and Fast Ethernet standards in order to provide increased bandwidth and interoperability among Ethernets.
gigabyte
One billion bytes. Abbreviated GB, Gbyte or G-byte.
gigascale integration
(GSI). ULSI (ultra large scale integration) packs millions of components onto a computer chip. Gigascale integration is a long-term goal of making chips with billions of components on them.
GIGO
Garbage In Garbage Out. The idea that if the data put into a computer or program is not good, the result the program comes back with will not be worth much.
GII
Global Information Infrastructure. The Clinton administration's term for the networks of the worldwide information superhighway.
Gilbreth, Frank Bunker
(1868-1924). The founder of modern motion study technique.
GIMP
GNU Image Manipulation Program or General Image Manipulation Program. Freely distributed software for photo retouching, image composition, and image authoring. This program for UNIX and X was written by Peter Mattis, Josh MacDonald, and Spencer Kimball, and released under the GNU General Public License (GPL).
GIMP ToolKit
(GTK). An object-oriented application programmers interface (API), written in C and primarily developed for use with the X Window System. GTK was originally developed as a toolkit for the General Image Manipulation Program (GIMP). It is becoming popular as an open source graphical user interface toolkit and has been used to develop free software.
GIPS
Giga-Instructions per Second. A measurement of the speed at which a processor executes instructions. The DEC Alpha AXP 21164 processor executes at 1 GIPS.
GIS
Geographic Information System. A computer system that has maps and geographic information, and sometimes analyses of geographic data. Geographic information systems have many uses including government, tourist information, education, environmental information, engineering, marketing.
GIX
Global Internet eXchange. A routing exchange point that helps networks all over the world to connect to the Internet.
glare filter
A screen placed in front of a computer display screen which reduces glare and helps the user avoid eyestrain.
glare guard
A screen placed in front of a computer display screen which reduces glare and helps the user avoid eyestrain.
glitch
A temporary malfunction; different from a bug, which is a recurring malfunction.
global
Worldwide; or throughout an entire file, program or system.
global character
A character that can be used to represent one or more other characters. In DOS and UNIX, ? can be used to represent any single character, and * can represent any group of characters. Therefore, “*.*” could be substituted for any file name; “*.EXE” would mean any .EXE file, etc.
global find and replace
A function that enables the user to search throughout a file for occurrences of a specified character string, and to automatically substitute another character string in each location where the first character string occurs.
global information infrastructure
(GII). The Clinton administration's term for the networks of the worldwide information superhighway.
Global Internet eXchange
(GIX). A routing exchange point that helps networks all over the world to connect to the Internet.
Global Network Navigator
(GNN). A collection of free services on the Internet, including The Whole Internet Catalog, the Internet Help Desk, and NetNews.
global search and replace
A function that searches throughout a file for a specified series of characters and replaces it in each location where it occurs with another specified series of characters.
Global System for Mobile communications
(GSM). A world standard for digital cellular communications.
Globally Unique Identifier
(GUID). A number embedded in Microsoft's Windows 98 operating system which could be used to track a user's network usage and other activities. The number, attached to software and even documents created by the user, made it possible to track applications that were used and documents that were created throughout a network. A Massachusetts computer programmer, Robert Smith, discovered the ID number embedded in documents he had created and later discovered the number had been sent to Microsoft, even after he instructed the application not to send it.
glossary
A list of keyboard shortcuts programmed by a particular user.
glyph
A symbol or character; in computer terminology, it refers to symbols or characters that can be printed by the computer.
GML
Generalized Markup Language. A language that can be used to identify the different parts of a document in a general way, which can be interpreted by different processing systems to make possible different presentations of the same information.
GMR
Giant Magneto Resistance. A technology for a read/write head which uses thin film layers to get a greater change in resistance, and is more sensitive than MR (Magneto Resistance).
GMS
1. General MIDI Standard. A standard designation of specific instruments to specific MIDI patch locations, so that a composition produced on one system will sound the same when played on another (notes originally assigned to trumpets will still be played by trumpets, etc.). GMS has 128 different sounds. 2. Global Messaging Service (Novell).
GMT
Greenwich Mean Time. The mean solar time of the meridian of Greenwich, England, used as the basis for calculating standard time throughout the world.
GNN
Global Network Navigator. A collection of free services on the Internet, including The Whole Internet Catalog, the Internet Help Desk, and NetNews.
GNOME
A free GNU program designed to work on all UNIX-like operating systems. Its three main components include: The GNOME desktop, The GNOME development platform and The GNOME Office. The GNOME project includes all images, source codes and data files so that users can modify any of the programs as they so choose, and then freely distribute the modified programs.
GNU
(GNU's Not UNIX!). A recursive acronym; the name of the Free Software Foundation's freely distributable replacement for UNIX.
GNU Image Manipulation Program
(GIMP). Also called General Image Manipulation Program. Freely distributed software for photo retouching, image composition, and image authoring. This program for UNIX and X was written by Peter Mattis, Josh MacDonald, and Spencer Kimball, and released under the GNU General Public License (GPL).
GNU's Not UNIX!
(GNU) The Free Software Foundation's freely distributable replacement for UNIX.
Gnutella
File-sharing technology offering an alternative to web search engines with an open-source, fully distributed “mini search engine” and file serving system for media and archive files that operates on a policy of file-sharing, no advertisements, greater privacy, and “no corporate dogma.”
Go
An ancient Oriental game of strategy which has become popular in the Western world and is available in computer format. Go is played via the Internet, on the Internet Go Server (IGS).
Gopher
A document retrieval system from the University of Minnesota. Through Gopher, a user can access files from many different computers by looking through hierarchical menus to find specific topics. A document may be a text, sound, image, or other type file. A program called Jughead can be used to search for topics found within Gopher files. Gopher sites can now be accessed through the World Wide Web.
Gopher client
A program which provides a user interface to Gopher.
Gopher server
A program which serves files to clients via Gopher.
GOPS
Giga (billion) Operations Per Second. A unit of measurement of computing speed.
GOSIP
Government OSI Profile. A U.S. Government specification for Open Systems Interconnection protocols.
GOTO
A statement that directs the computer to go to another part of a program or file.
GP
Gas Plasma.
GPL
General Public License. A license applied to software from the Free Software Foundation and the GNU project, which guarantees users the freedom to share the software and make changes in it.
GPRS
General Packet Radio Service. A global system for mobile communications (GSM) channel aggregation system that increases per-channel speeds from 9,600 to 14,400 bits per second (bps), adding data compression. With GPRS, mobile data transmissions can be as fast as 115,000 bps using the existing GSM base station infrastructure. GPRS technology works well with services such as wireless Internet, wireless intranet, and multimedia. One of the main benefits of this technology is that users are, in effect, always connected, and yet are only charged for the amount of data actually transmitted.
GPS
Global Positioning System. A system of satellites that transmit continually, which make it possible to identify earth locations through a receiving unit, by triangulation.
GPSL
General Purpose Scripting Language.
Graffiti
A handwriting recognition program from Berkeley Softworks.
grammar
A set of rules that defines the structure of a language, whether it is a natural language or a computer language.
grammar checker
A computer program that checks the grammar in a document, similar to a spelling checker.
Grammatik
A grammar checking program for Macintosh, DOS, Windows, and UNIX from WordPerfect Corporation.
graph
A picture that gives an overview of a collection of information, usually statistical or mathematical information. A graph can reveal trends that would be harder to recognize by just looking at numbers. Some kinds of graphs are a line graph, a bar graph, and a pie chart.
graph plotter
A device that draws images using ink pens that can be raised, lowered and moved over a page. The plotter uses vector graphics, making an image out of a series of point-to-point lines. Lines and curves are drawn on the page by a combination of horizontal and vertical movement of the pen or paper.
graphic
1. A symbol produced by a process such as handwriting, drawing, printing, engraving, etc. 2. An image in computer graphics format.
graphical browser
A browser that can display graphic images (pictures) in addition to text; examples are Netscape Navigator and Internet Explorer.
Graphical Device Interface
(GDI). The system by which graphics are displayed in Microsoft Windows. The application in use sends GDI the parameters for the image to be represented. GDI produces the image by sending commands to the monitor, printer, or other output device. Newer versions of Windows also have the DirectDraw interface, adding a faster mechanism for displaying games, full-motion video and 3-D objects. When the CPU is not busy, GDI updates the video display. When the CPU is busy, DirectDraw allows the application to communicate directly with the video adapter.
Graphical User Interface
(GUI). An interface that has pictures as well as words on the screen. Originally invented by Xerox, the idea was expanded and popularized by Apple Computers. With windows, icons, pull-down menus, and the mouse, the graphical user interface is easier to learn and work with.
graphics
The creation, editing, and printing of pictures. Computer graphics has two main methods: vector graphics (stored as a list of vectors) and raster or bitmap graphics (stored as a collection of dots or pixels).
graphics accelerator
An extra hardware added to a computer which speeds up graphics programs and adds more graphics capabilities.
graphics adapter
Also called graphics card, display adapter, or video adapter. A circuit board that enables a computer to display information on its screen. The resolution, number of colours, and refresh rate of a monitor is determined by the kind of graphics adapter used, plus the limitations of the monitor itself.
graphics card
Also called graphics adapter, display adapter, or video adapter. A circuit board that enables a computer to display information on its screen. The resolution, number of colours, and refresh rate of a monitor is determined by the kind of graphics card used, plus the limitations of the monitor itself.
graphics coprocessor
A separate, programmable integrated circuit inside a computer that aids the CPU by performing some of the computation necessary for displaying images on the screen, so that complex images can be displayed more quickly than they would be if the CPU had to do all the work.
Graphics Device Interface
(GDI). The system by which graphics are displayed in Microsoft Windows. The application in use sends GDI the parameters for the image to be represented. GDI produces the image by sending commands to the monitor, printer, or other output device. Newer versions of Windows also have the DirectDraw interface, adding a faster mechanism for displaying games, full-motion video and 3-D objects. When the CPU is not busy, GDI updates the video display. When the CPU is busy, DirectDraw allows the application to communicate directly with the video adapter.
Graphics Display Interface
(GDI). The system by which graphics are displayed in Microsoft Windows. The application in use sends GDI the parameters for the image to be represented. GDI produces the image by sending commands to the monitor, printer, or other output device. Newer versions of Windows also have the DirectDraw interface, adding a faster mechanism for displaying games, full-motion video and 3-D objects. When the CPU is not busy, GDI updates the video display. When the CPU is busy, DirectDraw allows the application to communicate directly with the video adapter.
graphics file
A file that contains only graphic images such as line drawings, paint program files, scanned images, photographs and other halftones, or type designs within a graphics file format. Though it may contain type, the type in a graphics file is presented as pictures and can not be edited with text editing methods.
graphics interchange format
(GIF). A graphics file format developed by CompuServe that uses LZW compression and 256 colors. GIF files are widely used on World Wide Web pages because they provide good-quality color images in a format that takes up a small amount of space. The GIF89 version allows one color of an image to be made transparent.
gray scale
1. A range of shades from white to black. 2. A printed scale showing the full range of grays and used in photography or to calibrate the shades on a computer display or printer. See gray-scale.
gray-scale or grayscale
Composed of a series of shades of gray. Gray-scale images have much more detail than line drawings (which are only white and black), and require much more storage space. High-resolution scanners can differentiate up to 256 different shades of gray.
Great Worm
The Internet Worm. A computer worm that in November 1988 infected over 6,000 computers on the Internet via the Sun UNIX sendmail program and other security loopholes.
greater than
ASCII character 62: > .
greek
In a mockup of a page layout, to represent text as abstract lines or symbols just to give an impression of where the text blocks will be. In traditional graphic design, such text areas were sometimes represented in Greek lettering. Some desktop publishing programs can be set up to do greeking.
green PC
An energy-saving computer, printer, or monitor that goes into a low-voltage mode when not used for a certain period of time. It returns to full-power mode when the keyboard or mouse is touched or a command is input.
Greenwich Mean Time
(GMT). The mean solar time of the meridian of Greenwich, England, used as the basis for calculating standard time throughout the world.
grep
A UNIX command to search a file for lines matching a pattern. From g / re / p: “globally search (for) / regular expression / (and) print (matching lines)”.
grephead
A UNIX fanatic (from the UNIX command grep).
grepper
A UNIX enthusiast (from the UNIX command grep).
grid lines
The crossing horizontal and vertical lines that make the boundaries of ce spreadsheet.
Grip
Front-end software for CD-rippers such as CDParanoia and cdda2wav. Grip allows you to rip entire tracks, or select a section of a track. It can call a chosen MP3 encoder to encode the resulting .wav file. It works like a CD player with CDDB lookup.
gross impressions
The number of times a page was downloaded by a user and an ad was potentially seen.
ground
A large electrically conducting body, such as the Earth, which is considered to have zero potential; or an object that makes an electrical connection with the Earth.
group icon
In Windows, an icon that represents a group of related files. Clicking on the group icon opens its window and shows the files in the group.
groupware
Software for people working together on a project. Groupware makes it possible for several people to work on the same file at once, via a network. It also helps with scheduling meetings and other kinds of group planning. Lotus Notes is a popular groupware package.
GSI
Gigascale Integration. ULSI (ultra large scale integration) packs millions of components onto a computer chip. Gigascale integration is a long-term goal of making chips with billions of components on them.
GSM
Global System for Mobile communications. A world standard for digital cellular communications using narrowband TDMA (Time Division Multiple Access), which allows up to eight calls at a time on 800 MHz and 1800 MHz frequencies. Introduced in 1991. Is the standard most commonly used in Europe and Asia, but not in the United States.
GT
Greater than: > .
GTK
(GIMP Toolkit). An object-oriented application programmers interface (API), written in C and primarily developed for use with the X Window System. GTK was originally developed as a toolkit for the General Image Manipulation Program (GIMP). It is becoming popular as an open source graphical user interface toolkit and has been used to develop free software.
GTL
Gunning Transceiver Logic.
GTO
Guide To Operations (IBM).
GUI
Graphical User Interface. An interface that has pictures as well as words on the screen. Originally invented by Xerox, the idea was expanded and popularized by Apple Computers. With windows, icons, pull-down menus, and the mouse, the graphical user interface is easier to learn and work with.
GUID
Globally Unique Identifier. A number embedded in Microsoft's Windows 98 operating system which could be used to track a user's network usage and other activities. The number, attached to software and even documents created by the user, made it possible to track applications that were used and documents that were created throughout a network. A Massachusetts computer programmer, Robert Smith, discovered the ID number embedded in documents he had created and later discovered the number had been sent to Microsoft, even after he instructed the application not to send it.
guide lines
In a graphics or page layout program, horizontal or vertical lines that can be pulled from the rulers at the sides of the file and placed on the page to help measure where to put different layout elements. The guide lines do not appear in the printout.
guiltware
Freeware or shareware that has a message attached which attempts to make the user feel guilty until making some kind of payment.
gutter
The space between columns in a page layout.
GVT
Global Virtual Time.
GWHIS
A World Wide Web browser for Windows, from Quadralay Corporation. GWHIS is derived from NCSA Mosaic.
gzip
A free downloadable compression-decompression utility from GNU.
gzipped
Compressed using gzip, a free downloadable compression-decompression utility from GNU.
h
1. A simple hypertext markup language. 2. An indication of a hexadecimal number; 09h is hexadecimal 9.
h-menu
Hierarchical menu. A pull-down menu that has sub-menus. The sub-menus are indicated by arrows. Putting the pointer on the item that has an arrow opens up the sub-menu. Sometimes a sub-menu will have arrows leading to sub-sub-menus.
h/w
Hardware; the physical part of a computer system; the machinery and equipment. Software means the programs that tell the computer what to do.
H1-B Visa
H1-B Visas may be used to bring a nonimmigrant worker to the United States if the employee is able to fill a position in a specialty occupation for professional position. The employee must prove that he/she is qualified for the position, holding a foreing degree equivalent to that required in the U.S. The visa can be granted from 1-6 years after which time he/she must reside outside the U.S. for at least one year.
hack
1. To use ingenuity and creativity to solve computer programming problems, to overcome the limitations of a system and expand its capabilities. 2. A solution to a programming problem. 3. A clever yet harmless practical joke.
hacker
1. One who is knowledgeable about computers and creative in computer programming, usually implying the ability to program in assembly language or low-level languages. A hacker can mean an expert programmer who finds special tricks for getting around obstacles and stretching the limits of a system. 2. To some people it means an unconventional programmer or one who is not formally trained, or one who jerry-rigs programs (making temporary fixes that are not well-done). 3. At MIT, a “hack” means a practical joke, especially one that requires intelligence and technological skill to carry out.
hairline rule
A very thin line, often used as a design element in page layouts.
HAL
Hardware Abstraction Layer. A translation protocol in Windows NT for porting NT to another platform.
half-adder
A logic circuit in the arithmetic and logic unit of a computer that adds two one-digit binary numbers, producing a result bit and a carry bit. A half-adder consists of an XOR gate and an AND gate; a full-adder consists of half-adders and other switches.
half-duplex
A communications channel which transmits data in either direction, but only one direction at a time.
half-inch tape
Magnetic tape cartridge drives used for backup with mainframes and minicomputers.
halftone
A reproduction of a grayscale image which uses dots of varying size or density to give the impression of areas of gray.
hand coding
Writing a program in a programming language, rather than using high-level programming tools to create the program.
hand tool
In graphics programs, a pointer shaped like a hand that is used to select and move things onscreen.
hand-held scanner
A scanner that is held in the hand and passed across the image to be
scanned. Hand-held scanners are less expensive than desktop scanners, but
require a steady hand to get a clear image.
handle
A nickname that is used online.
handles
In graphics programs, handles are little squares that appear at the edges of selected images or text blocks, which can be used to change the size, shape, or orientation of the selected material.
handoff
The transfer of an ongoing wireless call from one transmission site to another without disconnecting the call.
handset
The part of a telephone that is held in the hand, containing the speaker
and microphone.
handshake
The greeting between two modems, which can be heard as an annoying grating and squealing sound. The handshake introduces the modems to each other so they can establish the transmission speed they will use, whether they will use error correction or compression, and other agreements about how they will exchange information.
handshaking
The exchange of signals back and forth over a communications network to establish a valid connection between two computers.
hanging indent
A paragraph in which the first line begins at the left margin, and the rest of the lines are indented. Hanging indents are sometimes used when the first line begins with a number and a space before the text, and succeeding lines are indented to where the text begins in the first line.
hanging paragraph
A paragraph with a hanging indent; every line but the first line is indented from the left margin.
hard boot
Booting a system from power off. Sometimes a computer which is “locked up,” or “frozen,” must be turned off and on again to clear the memory before it can be operated. A soft boot is restarting the computer without turning the power off.
hard copy
The paper version of a document, as opposed to the version on disk or tape.
hard disk
The main device that a computer uses to store information. Hard disks are rigid aluminum or glass disks about 3.5″ in diameter in a personal computer, and smaller in a laptop. They are coated with ferromagnetic material and rotate around a central axle. Data is transferred magnetically by a read/write head. A hard disk drive for a personal computer may contain as many as eight hard disks, rotating around the same axle. Most hard disks are permanently connected to the drive, but there are removable hard disks. Hard disk access time (the amount of time it takes to retrieve data) is measured in milliseconds.
hard disk drive
(HDD). A disk drive that reads from and writes to a hard disk.
hard drive
(HD). Hard disk drive. A disk drive that reads from and writes to a hard disk.
hard hyphen
A hyphen that is always set; for example, the hyphen in “cost-effective.” A soft hyphen, by contrast, will only be set when a word that is not normally hyphenated falls at the end of a line, and must be broken for proper type spacing.
hard page break
A page break inserted by the user with a command in the program. A page will end at a hard page break even if it only has a few lines on it; the bottom of the page will be left blank.
hard return
A hard return sends the cursor down to the next line, and is made by pressing the return key; it is equivalent to a carriage return on a typewriter.
hard space
A space character that is treated by the machine like a letter, used when the typesetter does not want a line break in the middle of a phrase, multiple-word proper name, or series of ellipses. Also called a fixed space.
hard-coded
Referring to instructions that are written directly into a program and therefore cannot be easily modified, rather than instructions that can be modified by a user.
hardware
The hardware is the physical part of a computer system; the machinery and equipment. Compare with software
hardware handshake
Handshaking signals between two computers which are carried by voltage levels or pulses on wires. A software handshake communicates the same information by way of characters inserted into the data stream. Computers use handshaking signals to indicate to each other when to start or stop sending data.
hardware handshaking
Sending signals between two computers that indicate to each other when to start or stop sending data. The handshaking signals are carried by voltage levels or pulses on wires. A software handshake can communicate the same information using characters inserted into the data stream.
hardware monitor
A device that monitors the hardware circuits of a computer for the purpose of checking the performance of the system.
hardware platform
The CPU family which is the basis for a particular machine. Each hardware platform has its own machine language, and all software used by it must use that language. Some examples of hardware platforms are: x86 (Intel CPU: used by PCs); 680×0 (Motorola CPU: used by Macs); PowerPC (Apple, IBM, Motorola CPU: used in PowerMacs); VAX (Digital minicomputers); S/370 (IBM mainframes); Unisys (Unisys mainframes); SPARC (Sun); CDC (CDC mainframes and midrange computers); PA-RISC (HP workstations and minicomputers).
hardwired
1. Having a direct physical connection, such as by wire or cable. 2. Controlled by wiring of the hardware, rather than by software.
harmonic distortion
Undesired harmonic frequencies that result from irregularities in a transmission line.
Harvest
A powerful, fast and flexible data retrieval program that allows searchers to use keywords to quickly locate files. Search results display lines from the files containing the search string and full paths to the files. The Harvest site (http://harvest.cs.colorado.edu/) provides detailed instructions and online help.
hash mark
ASCII character 35: # . Also called number sign, because it is used to stand for “number;” or pound sign, because it is used to stand for “pound.”
hat
ASCII character 94: ^ , also called circumflex.
Hayes commands
The standard set of commands used by the Hayes modem, which are widely used by other modems (called Hayes-compatible).
Hayes Microcomputer Products, Inc.
A modem manufacturer in Atlanta, GA. Many modems are designed to be compatible with Hayes modems, which have set a standard.
Hayes Smartmodem
Intelligent modems for personal computers from Hayes Microcomputer Products, Inc., Atlanta, GA. The commands used by the Hayes modems have become an industry standard and are now used by many other modems.
Hayes Standard AT Command Set
The set of commands used by Hayes modems, which became an industry standard and are widely used by other modems as well.
Hayes-compatible modem
A modem which understands the same set of commands as the Hayes modem.
HCI
Human-Computer Interaction. The study of how humans interact with computers, used to design computers which are easy for humans to use.
HCSS
High Capacity Storage System.
HCU
Home Computer User.
HD
1. Hard Disk. 2. High Density.
HDA
Head Disk Assembly. The mechanical parts of a disk drive, including the read/write heads, platters, and other non-electronic components.
HDD
Hard Disk Drive. A disk drive that reads from and writes to a hard disk.
HDSC
High Density Signal Carrier (DEC).
HDSL
High-Speed Digital Subscriber Line. A transmission method that makes it possible to transmit data at high speeds over ordinary copper telephone wires. See ADSL.
www.hp.com.
HEX
Hexadecimal. The base 16 numbering system, sometimes used as a short way of representing binary numbers. The digits 0-9 are used, plus the letters A-F which stand for numbers 10 to 15. The farthest-right digit is the ones place; the digit next to the left is the 16s place; the next place to the left is 16^2 = 256, etc. Each place is 16 times the place immediately to the right of it.
hexadecimal
The base 16 numbering system, sometimes used as a short way of representing binary numbers. The digits 0-9 are used, plus the letters A-F which stand for numbers 10 to 15. The farthest-right digit is the ones place; the digit next to the left is the 16s place; the next place to the left is 16^2 = 256, etc. Each place is 16 times the place immediately to the right of it.
hexit
Hexadecimal digit. Hexadecimal numbers use the digits 0-9, then A=10, B=11, C=12, D=13, E=14, F=15.
HF
1. High Frequency. Electromagnetic frequencies in the range of 3 to 30 megaherz. 2. Human Factors. The physical and psychological requirements of human beings that must be considered when designing computer systems and programs, in order to make products that are practical, efficient, and easy to use.
HFS
Hierarchical File System. A system in which data is stored hierarchically in directories and subdirectories (as in DOS), or folders within folders (as in Macintosh). Most operating systems have hierarchical file systems.
HGML
Hypertext General Markup Language. A formatting code for marking up text files, which makes up part of SGML.
hidden file
A file that ordinarily is not visible in the file directory and cannot be accessed by unauthorized users. Some operating system files are hidden, to prevent inexperienced users from inadvertently deleting or changing these essential files. Some file utility programs also allow users to hide files. In DOS and DOS-related operating systems, the dir command lists all files except hidden files. In versions of DOS since 5.0, the command dir /ah will list hidden files. In UNIX, the ls command lists all files except hidden files (files whose names begin with a dot); the command ls -al lists the hidden files.
hide
In a graphical user interface, a menu selection that instructs the computer not to show certain things on screen; for example, hard returns, the toolbox, guide lines, etc. The opposite command is “show . . . “.
hierarchical file system
(HFS). A system in which data is stored hierarchically in directories and subdirectories (as in DOS), or folders within folders (as in Macintosh). Most operating systems have hierarchical file systems.
hierarchical menu
(Also called h-menu). A pull-down menu that has sub-menus. The sub-menus are indicated by arrows. Putting the pointer on the item that has an arrow opens up the sub-menu. Sometimes a sub-menu will have arrows leading to sub-sub-menus.
hierarchical routing
Dividing a network into a hierarchy of smaller networks, and making each level responsible for its own routing. The Internet has three levels in its hierarchy: backbones, mid-level networks, and stub networks. Backbones are responsible for routing between mid-level networks, mid-levels route between sites, and each site does its own internal routing.
Hierarchical Storage Management
(HSM). An automatic system that moves files from hard disk to other storage media after a certain length of time, or according to other specifications of the user.
HIFD
High Density Floppy Disk. Currently high-density floppy disks are 1.4 MB. Density refers to the amount of data stored per square inch.
high ASCII
ASCII defines code numbers for 128 characters, which are the alphabetic and numeric characters on a keyboard and some additional characters such as punctuation marks. High ASCII includes additional ASCII characters up to 256, which may include foreign language accents, math symbols, trademark and copyright symbols, etc. These characters are not the same on all computers.
high bit
The most important bit in a byte.
high definition television
(HDTV). The next standard in television and video, which will have higher resolution, better color, and better audio. There are both analog and digital versions of HDTV.
high frequency
(HF). Electromagnetic frequencies in the range of 3 to 30 megaherz.
high performance addressing
(HPA). A kind of display used on some multimedia notebook computers, that delivers high-quality graphics comparable to Active Matrix (TFT) Displays.
High Performance Computing and Communica
(HPCC). A U.S.government plan to increase people's computer knowledge by creating scientific workstations, experimental systems, and a high-speed network linking government agencies, private companies, and schools with supercomputer systems.
High Performance File System
(HPFS). The file system for IBM OS/2.
HIgh Performance Parallel Interface
(HIPPI). A high-speed communications bus used over short distances with supercomputers or high-speed LANs. It may be used within a computer room to connect a supercomputer with other computers, routers, and peripherals.
High Performance Serial Bus
A Macintosh and IBM PC serial bus interface standard (IEEE 1394), which provides high-speed communications and can support up to 63 peripherals. It allows devices hooked to it, for example a scanner and a printer, to communicate with each other without having to use the system memory or the CPU.
high resolution
The high number of dots per square inch required to produce a high-quality image in printing or on a computer display screen. The higher the resolution, the finer the image quality. Good laser or inkjet printers and scanners provide a resolution of 600 dots per inch; high-quality typesetting machines can print at 2,540 dpi.
High Sierra
The first format for recording files and directories on CD-ROMs, which has been replaced by ISO 9660.
High Sierra Format
(HSF). A logical format and file structure for CD-ROMs that paved the way for ISO 9660. As the industry began to evolve many different proprietary CD-ROM formats, the need for a common standard became obvious. A meeting was held at Del Webb's High Sierra Hotel and Casino, in Lake Tahoe, Nevada, at which representatives from various companies worked together to arrive at a standard. The result of this meeting was “Working Paper for Information Processing: Volume and File Structure for CD-ROM Information Exchange (1986),” which became known as the High Sierra Format. Later, HSF was modified and evolved into ISO 9660, the key standard for worldwide acceptance of CD-ROMs.
High-bit-rate Digital Subscriber Line
(HDSL). Or High-speed Digital Subscriber Line. A transmission technology that can send data at high speeds over regular copper telephone lines. Unlike ADSL, HDSL transmits data at the same speed in both directions, typically 784Kbps.
high-density
(HD). Having high storage capacity per unit of area. High-density disks store more information than double-density disks, but less than extra-high-density disks. Currently, high-density 3.5″ floppies are 1.4 MB. The 3.5″ high-density floppy disk has an HD logo on it and has two holes at the top. High-density 5.25″ disks are1.2MB.
high-level language
(HLL). A language for programming computers which does not require detailed knowledge of a specific computer, as a low-level language does. High-level languages do not have to be written for a particular computer, but must be compiled for the computer they will work with. High-level languages are closer to human language than low-level languages, and include statements like GOTO or FOR which are regular words.
high-speed digital subscriber line
(HDSL).A form of DSL, HDSL is a transmission method that makes it possible to transmit data at high speeds (1.544 Mbps in both directions) over ordinary copper telephone wires. See ADSL.
high-tech
High technology. Refers to the latest developments in technology.
highlight
To select text or graphics for moving, editing, or deletion. Text can be selected by dragging the cursor over it; an image by clicking on it. A highlighted area of text appears in a different color from the other text; for example, white with a black background. Highlighted graphics show in other ways.
HIMEM
HIgh MEMory. A DOS and Windows extended memory manager.
HIPPI
HIgh Performance Parallel Interface. A high-speed communications bus used with supercomputers or high-speed LANs.
hiragana
A character set of symbols used in one of the two main Japanese phonetic alphabets, in which each character takes up 1 byte.
hit
1. One visit to a World Wide Web page by a user. Many servers have counters on their home pages to tell how much traffic they are getting. 2. A cache hit is a successful retrieval of data from a cache.
HITL
Human Interface Technology Laboratory. The Human Interface Technology Laboratory at the University of Washington, a center of research and development in new interface technology.
HLS
Hue, Luminance, Saturation. A color model.
HMA
High Memory Area. An area that extends the memory of a PC.
HMD
Head Mounted Display. A helmet with stereoscopic goggles for the wearer's eyes, and stereo headphones over the ears; used as an interface through which the wearer can experience a virtual reality environment.
Hollerith card
A kind of punch card which can be punched with hole patterns in 80 columns and 12 rows.
Hollerith machine
The earliest automatic data processing system, developed by Herman Hollerith. The Hollerith machine was used to count the United States 1890 census. The data was recorded on hand-punched cards and counted by means of a tabulating machine.
Hollerith, Herman
An American inventor (1860-1929). He invented the punched card and the Hollerith machine for tabulation. His machine was used for the U.S. Census of 1890. He formed the Tabulating Machine Company in 1896. In 1911, it merged with several other companies and became the Computing-Tabulating-Recording Company, precursor to IBM.
holostore
A method of data storage. The data is stored as a holographic (3-dimensional) image by passing light through light-sensitive crystals that retain the light patterns.
home key
The key in some programs that moves the cursor to the beginning of the current line, or in combination with the control key, moves the cursor to the beginning of the document.
home page
The first page on a World Wide Web site, to which supporting pages are linked.
homepage
The first page on a World Wide Web site, to which supporting pages are linked.
homogeneous environment
A computing environment in which hardware and system software come from the same vendor.
Honeywell
Originally, a manufacturer of temperature control devices. Honeywell’s Information Systems division became one of the first major computer companies in the United States, producing advanced, high-performance computers. Honeywell took over General Electric computers, then later was taken over by Bull to become part of Bull HN.
hook
A feature of software or hardware that is included in order to provide for future expansion. In programming, for example, a hook may be instructed to call an outside routine, or may allow for entry of a variable. The more hooks, the more the product allows for additions or changes.
hookemware
Free software that gives a limited sample of how a program works, intended to hook the user into buying the full version.
hop
In communications routing, a transmission from one network node to another. A message sent over a long distance may need to make a series of hops to get from its source to its destination.
Hopper, Grace
Rear Admiral Grace Hopper, U.S. Navy (1906-1992); originator of the concept of the compiler, and developer of the first commercial high-level language, which evolved into COBOL.
Hopper’s rule
Electricity travels one foot in a nanosecond (a billionth of a second). The speed that electricity can travel limits the speed at which signals can travel in an electric circuit, and therefore limits the possible speed of a computer.
horizontal application
An application used by many different kinds of organizations, such as word processing or bookkeeping software. Contrast vertical application.
horizontal resolution
The number of pixels per horizontal line, or the number of columns in a matrix.
horizontal scaling
Adding more computer systems to a multiprocessing environment, in contrast to vertical scaling, in which more processors are added to the same computer system.
horizontal scan frequency
The number of scan lines per second displayed on a monitor screen, expressed in kilohertz.
horizontal scan rate
(HSR). The number of scan lines displayed per second on a computer monitor, expressed in kilohertz (kHz).
horizontal software
Software used by many different kinds of organizations, such as word processing or bookkeeping software. Contrast vertical software.
host
1. A computer connected to a network, that provides data and services to other computers. Services may include data storage, file transfer, data processing, e-mail, bulletin board services, World Wide Web, etc. 2. A multiuser computer that has terminals attached to it.
host computer
1. A computer connected to a network, that provides data and services to other computers. Services may include data storage, file transfer, data processing, email, bulletin board services, World Wide Web, etc. 2. A multiuser computer that has terminals attached to it.
host name
The unique name that identifies a computer on a network. On the Internet, the host name is in the form “comp.xyz.net”; if there is only one Internet site the host name is the same as the domain name. One computer can have more than one host name if it hosts more than one Internet site, however (for example, “home.xyz.net” and “comp.xyz.net”); in that case “comp” and “home” are host names and “xyz.net” is the domain name.
hot fix
Repair of a component while it is operating.
Hot Key
A key or combination of keys that can either switch a user to a different program, or causes another function to occur in the computer. Usually, it is used to activate a terminate-and-stay-resident (TSR) program.
hot potato routing
A way of routing messages in a network in which each message is immediately sent on its way as soon as it arrives.
hot swap
To remove and replace a component of a system while the power is on and the system is still operating.
HotDog
A fast, flexible, and user-friendly Web page editor from Sausage Software, http://www.sausage.com/ .
High Performance Addressing. A kind of display used on some multimedia notebook computers, that delivers high-quality graphics comparable to Active Matrix (TFT) Displays.
HPCC
High Performance Computing & Communications. A U.S.government plan to increase people's computer knowledge by creating scientific workstations, experimental systems, and a high-speed network linking government agencies, private companies, and schools with supercomputer systems.
HPFS
High Performance File System. The file system for IBM OS/2.
HS
High Speed. A modem status signal indicated by a light on the modem, which means the modem is currently operating at its highest transmission rate.
HSB
Hue, Saturation, Brightness. A method of describing color. Hue is the color itself; saturation is how pure the color is; and brightness is how light or dark the hue is.
HSF
High Sierra Format. A logical format and file structure for CD-ROMs that paved the way for ISO 9660. As the industry began to evolve many different proprietary CD-ROM formats, the need for a common standard became obvious. A meeting was held at Del Webb's High Sierra Hotel and Casino, in Lake Tahoe, Nevada, at which representatives from various companies worked together to arrive at a standard. The result of this meeting was “Working Paper for Information Processing: Volume and File Structure for CD-ROM Information Exchange (1986),” which became known as the High Sierra Format. Later, HSF was modified and evolved into ISO 9660, the key standard for worldwide acceptance of CD-ROMs.
HSI
Hue, Saturation, Intensity.
HSM
Hierarchical Storage Management. An automatic system that moves files from hard disk to other storage media after a certain length of time, or according to other specifications of the user.
HSR
Horizontal Scan Rate. The number of scan lines displayed per second on a computer monitor, expressed in kilohertz (kHz).
HSV
Hue, Saturation, Value. A color model similar to HSB (Hue, Saturation, Brightness).
HTML
HyperText Markup Language. The language used to create World Wide Web pages, with hyperlinks and markup for text formatting (different heading styles, bold, italic, numbered lists, insertion of images, etc.).
HTML tags
Codes in HTML that give instructions for formatting or other actions. World Wide Web documents are set up using HTML tags which serve various functions such as controlling the styling of text and placement of graphic elements and providing links to interactive programs and scripts. Examples of tags are baseline return, which creates a line break;
. . .
a pair of tags that horizontally center the enclosed text; image source, used to insert a graphic image into an HTML document.
HTML validation
Bringing an HTML-coded page into compliance with established HTML standards. There are a number of validation sites on the Internet that provide the service of checking an HTML page and identifying any problems. The reason for validating an HTML page is to make sure it can be read by the different browsers that are in use.
HTML+
An extended version of the original HTML, which expanded HTML's ability to handle documents containing multimedia objects.
HTML+TIME
Time Extensions for HTML. A proposal by Compaq, Microsoft, and Macromedia to extend time capability into a Web browser. HTML+TIME includes a set of elements and attributes to include time in a document, and a mechanism to turn it into a time-based presentation. HTML+TIME reuses concepts and techniques of SMIL (Synchronized Multimedia Integration Language, which makes possible the broadcast of television-like content on the Web), but with some simplification and improvement. Using HTML+TIME, authors do not have to learn a programming language for writing timed HTML presentations.
HTTP
HyperText Transfer Protocol. The protocol most often used to transfer information from World Wide Web servers to browsers, which is why Web addresses begin with http://. Also called Hypertext Transport Protocol.
HTTP cookie
A packet of information which an HTTP server sends to a World Wide Web browser, to be sent back by the browser every time it reconnects with that server. HTTP cookies can be used to identify registered users.
HTTPd
Hypertext Transfer Protocol daemon. A World Wide Web server from NCSA, which is compatible with HTTP/1.0.
HTTPS
HyperText Transmission Protocol, Secure. Netscape's version of HTTP for secure transactions.
hub
Like the hub of a wheel, a central device that connects several computers together or several networks together. A passive hub may simply forward messages; an active hub, or repeater, amplifies or refreshes the stream of data, which otherwise would deteriorate over a long distance.
hub ring
In a 5.25″ floppy disk, the ring around the hole.
huff
To compress data using Huffman code. See puff.
Huffman coding
A character coding technique for data compression; the complete set of codes can be represented as a binary tree called a Huffman tree.
human factors
(HF). The physical and psychological requirements of human beings that must be considered when designing computer systems and programs, in order to make products that are practical, efficient, and easy to use.
Human Interface Technology Laboratory
(HITL). The Human Interface Technology Laboratory at the University of Washington, a center of research and development in new interface technology.
human-computer interaction
(HCI). The study of how humans interact with computers, used to design computers which are easy for humans to use.
human-computer interface
The interface between a human and a computer; for example, a command line interface, a graphical user interface, virtual reality interfaces.
hung
Referring to a state in which a system is up and running but for some reason cannot complete a process; the system can do some things but is not fully functional.
Hungry Programmers
A group of programmers who create free software; their home page is at http://www.hungry.com/.
hunt and peck
A way of typing using only one or two fingers and visually finding each key, slower than touch typing with all ten fingers.
hunt-and-peck
Describing a method of typing by using only one or two fingers and visually finding each key, slower than touch typing with all ten fingers.
HVD
High Voltage Differential
HWD
Height Width Depth.
hybrid
Combining two different technologies or systems.
hybrid computer
A computer which is a combination of analog and digital computer systems. A hybrid computer uses analog-to-digital conversion and digital-to-analog conversion, and may input or output either analog or digital data. One use for these computers is in robotics. See analog computer, digital computer.
HyperCard
A data management program developed for Apple and Macintosh computers. It organizes information into stacks of cards (as seen on the computer screen, not usually printed and made into hard copy). Each card can contain text, graphics, sound, animation, and video. A user can read the cards one at a time like the pages of a book, or follow a thread that jumps from card to card by means of hypertext links. A HyperCard stack can be used for something simple like a collection of recipes; more complex links would be needed for an organizational flow chart; even more sophisticated would be an interactive multimedia presentation with many possible paths to take through the information. With HyperCard and the HyperTalk programming language, users can develop their own applications. Similar programs for PC are HyperPad and ToolBook.
hypergraphic
A link connected with a graphic image; the graphic equivalent of hypertext. Clicking on the image activates the link.
hyperlink
A link in an HTML document that leads to another World Wide Web site, or another place within the same document. Hyperlinks are usually underlined or shown in a differentcolor from the surrounding text. Sometimes hyperlinks are pictures.
hypermap
An interactive map with hyperlinks that lead to more detailed information about each particular area.
hypermedia
The linking of multimedia to Web documents; the integration of text, images, sound, graphics, animation, and video through hyperlinks.
HyperPAD
A program for PCs that is similar to HyperCard for Macintosh. HyperPAD is from Brightbill-Roberts & Company.
HyperTalk
A programming language used with HyperCard.
hypertext
Text that has hyperlinks. When hypertext is viewed with an interactive browser, certain words appear as highlighted by underlining or color; clicking on a highlighted link leads to another location with more information about the subject. The term was invented by Ted Nelson.
Hypertext General Markup Language
(HGML). A subset of SGML (Standard Generalized Markup Language).
Hypertext Markup Language
(HTML). The language used to create World Wide Web pages, with hyperlinks and markup for text formatting (different heading styles, bold, italic, numbered lists, insertion of images, etc.).
Hypertext Transfer Protocol
(HTTP). The protocol most often used to transfer information from World Wide Web servers to browsers, which is why Web addresses begin with http://.
HyperText Transmission Protocol, Secure
(HTTPS). Netscape's version of HTTP for secure transactions.
hyphen drop
The automatic dropping of a hyphen when it is not necessary to divide a word; for example, when the text block is made wider or narrower, and the end of the line comes in a different place.
hyphen ladder
Hyphens at the end of three or more consecutive lines; considered by style by editors.
hyphenation
Breaking a word with a hyphen to keep a line from being too long. Word processing programs usually hyphenate words automatically using a hyphenation dictionary.
hyphenation dictionary
A file, usually in a word processing or desktop publishing program, which defines where hyphens will be placed for common words.
hyphenation zone
A distance from the right margin within which a word will be hyphenated if needed to make the line space properly.
HYTELNET
(HYpertext browser for TELNET Network accessible sites). Hytelnet is also Peter Scott's hypertext database of over 1800 publicly accessible Internet sites, including libraries, Campus-Wide Information Systems, gopher, WAIS, WWW systems, Freenets, and more. HYTELNET software for PC, Macintosh, Unix and VMS systems is available via anonymous ftp from ftp.usask.ca (128.233.3.11) in the /pub/hytelnet directory. The Macintosh, Unix and VMS versions make automatic telnet connections to remote sites. There is also a Hytelnet mailing list, HYTEL-L.
Hz
Hertz. The number of cycles per second of an electromagnetic wave; one Hz is equal to one cycle per second. The name comes from Heinrich R. Hertz, the German physicist who discovered electromagnetic waves.
I-beam pointer
The onscreen pointer when it is in the shape of an I.
I-Comm
A World Wide Web graphical browser for IBM PCs with Windows or OS/2, downloadable as shareware.
i-way
Information superhighway.
I/O
Input/Output. Transfer of data into a computer, and from the computer to the outside world.
I/O address
Input/Output address. A unique address given to a peripheral device for input and output; on a PC, the I/O address is in the form of a three-digit hexademical number.
I/O area
A memory area that temporarily holds data from an input device, or data which will be sent to an output device.
I/O device
Input/Output device. A device that is used to transfer data into or out of the computer; also called peripheral device.
i860
A RISC chip developed by Intel, used in Stratus computer systems.
IAB
Internet Architecture Board, formerly Internet Activities Board. The technical body that governs the Internet. It has two task forces: the Internet Research Task Force (IRTF), which explores new technologies, and the Internet Engineering Task Force (IETF), which develops standards.
IAC
1. Inter Application Communications. In Macintosh System 7 and above, the exchange of communication between one application and another. 2. In Any Case (chat).
IAITS
It’s All In The Subject . IAITS is the only content in the body of an email where the message is contained in the subject line. For example, the subject of the message could be "I want my money back now!" The body of the email would say simply, IAITS.
IANA
Internet Assigned Numbers Authority. The authority responsible for assigning numbers (such as port or socket numbers) in the Internet Suite of Protocols. For number assignments, email [email protected]
IAP
Internet Access Provider. An organization or company which provides Internet access to individuals, businesses, or other groups. An IAP may provide leased line services for dedicated high-speed access, and dial-up accounts that use a modem and a regular telephone line. Major online services such as America Online and CompuServe often are also Internet access providers.
IAS
A machine that many consider to be the first modern computer, built by Jon von Neumann for the Institute for Advanced Studies.
International Business Machines Corporation, Armonk, NY. The world's largest computer company, begun in New York in 1911 as the Computing-
Tabulating-Recording Company and renamed IBM in 1924. IBM sold
tabulating machines and punch cards from the 1920s through the 1960s, and started selling computers in 1953. IBM sells mainframes, minicomputers, workstations, personal computers, and software, including the OS/2 operating system. In 1991, IBM joined with Apple Computer and Motorola to produce the PowerPC chip.
IBM Advanced Technology PC
(AT). An IBM PC introduced in 1984 that was the most advanced PC at that time, with an Intel 80286 processor, 16-bit bus, and 1.2MB floppy drive.
IBM compatible
A personal computer that is compatible with the IBM PC.
IBM PC
International Business Machines Personal Computer. PCs and compatibles are used more than any other computer systems in the world.
IBM PC AT
(Advanced Technology). An IBM PC introduced in 1984. It was the most advanced PC at that time, with an Intel 80286 processor, 16-bit bus, and 1.2MB floppy drive.
IBM PC XT
(Extended Technology). The first IBM PC to have a hard disk. It came out in 1983. It had an Intel 8088 microprocessor, 128KB of RAM, and a 10MB hard drive.
IBM PCjr
(PC junior). The first home computer from IBM, introduced in 1983. It had a chiclet keyboard, floppy disks, and an Intel 8088 microprocessor. Some of them had a mouse and popup menus.
IBM-GL
IBM – Graphics Language.
IC
1. Integrated circuit. Also called microelectronic or chip. A microelectronic device comprising many miniature transistors and other electronic components on a single thin rectangle of silicon or sapphire, approximately 1/16" to 5/8" on a side, and 1/30" thick. An integrated circuit can contain dozens, hundreds, or millions of electronic components. To make a chip, impurities are added to the supporting material, or substrate, in specific places to create P-type and N-type regions; then by projecting light onto light-sensitive chemicals, polysilicon or aluminium tracks are etched into the top 1/1000" of the substrate to make the electronic circuits. Chips come in analog, digital and hybrid types. Compared with earlier technology, microelectronics are faster, more compact, more energy-efficient, and cheaper to manufacture. The most complete integrated circuit is a microprocessor: a computer on a single chip. 2. In Character. The mode used when playing a character in a role-playing game (RPG). See OOC (Out of Character). 3. I See (chat).
Institute for Certification of Computer Professionals. An organization in Des Plaines, IL, U.S.A. that certifies computer professionals in many countries. Certification is given on the basis of tests, academic credit, and/or job experience. The different types of certification are: Associate Computer Professional (ACP), Certified Computer Programmer (CCP), Certified Data Processor (CDP), and Certified Systems Professional (CSP).
ICE
Information and Content Exchange. A protocol based on XML which will make it easier for large businesses and organizations to manage and exchange information and assets via networks, using secure transactions. ICE can be used by syndicated publishing networks, Web superstores, and online resellers to automate many transactions and reduce the cost of doing business online.
ICMP
Internet Control Message Protocol. An extension to the Internet Protocol which is used to communicate between a gateway and a source host, to manage errors and generate control messages.
ICO
Icon file extension
iCOMP
Intel Comparative Microprocessor Performance index. A benchmark used by Intel to compare the performance of microprocessors.
icon
In a graphical user interface, a small picture on the screen which represents something. Files and programs have icons, and open when the user clicks twice on the icon. There is an icon to show which program is currently running. Moving and copying files is done by dragging their icons to the desired location. A file is deleted by moving its icon to the picture of a trash can.
ICQ
("I Seek You"). A chat program from Mirabilis for Windows 95. It can be set to notify the user when friends are online; it seeks out friends of the user so messages and files can be exchanged.
ICR
Intelligent Character Recognition. The ability of a computer to recognize hand-printed characters or typeset characters that are unclear.
ICS
Intergraph Computer Systems. A Huntsville, Alabama computer manufacturer. Intergraph develops, manufactures, sells, and supports computer systems for the Technical Desktop. Some products are Intel-based TD personal workstations, TDZ 3D workstations, servers, peripherals, and interactive computer graphics systems.
ICVerify
ICVerify is a program which lets you use your PC as a credit card terminal. You can process credit cards, ATM and debit cards, and approve checks.
ICW
Interactive CourseWare. A U.S. military term for software used with computer-aided instruction and computer-based training. Interactive CourseWare relies on interaction with the trainee to determine the pacing and sequence of a course of instruction.
ID
Identification.
IDAPI
Integrated Database API . Borland database programming interface.
IDC
International Data Corporation. A Framingham, Massachusetts company that does market research and analysis on all aspects of information technology.
IDDE
Integrated Development & Debugging Environment (Symantec).
IDE
1. Integrated Drive Electronics. Interface for connecting additional hard drives to a computer. 2. Integrated Development Environment (Borland). 3. Interactive Development Environment. A set of programming tools to help the user write software.
idle time
Time during which a machine is operational, but not in use.
IDMS
Integrated Database Management System. A relational database management system for minicomputers and mainframes.
IDNS
Internet Domain Name System.
IE
1. Internet Explorer. A graphical World-Wide Web browser from Microsoft for Microsoft Windows, Windows 95, Windows NT, and Macintosh. It can be downloaded from the Internet. 2. Information Engineering. The methods and technologies used to process information within an organization.
IEC
International Electrotechnical Commission. An organization in Geneva that sets international standards for the electrical and electronics fields. IEC created the Joint Technical Committee for information technology with ISO.
www.ieee.org.
ieee
Top-level newsgroup category for an IEEE (Institute of Electrical and Electronics Engineers) newsgroup.
IEEE Computer Society
The Computer Society of the Institute of Electrical and Electronics Engineers holds conferences on computers and technology, and publishes a journal called Computer.
IESG
Internet Engineering Steering Group. Executive committee of the Internet Engineering Task Force.
IETF
Internet Engineering Task Force. An international group of network designers, operators, vendors, and researchers who coordinate the management and evolution of the Internet, addressing issues of protocol and architecture. The IETF submits proposals for standards to the Internet Architecture Board.
IFIP
International Federation for Information Processing. An international federation of professional and technical organizations in Geneva, Switzerland, concerned with information processing. There is one representative organization from each country; the United States representative is FOCUS. IFIP does research to help develop standards, and advises the International Telecommunications Union.
IGC
Institute for Global Communications. An organization dedicated to using computer networks to further the causes of peace, human rights, and preserving the environment. The IGC promotes the use of high technology to improve international communication and information exchange. IGC networks include PeaceNet, EcoNet, ConflictNet and LaborNet.
IGMP
Internet Group Multicast Protocol.
IGP
Interior Gateway Protocol. An Internet protocol which provides routing information to the routers within an autonomous network.
IGRP
Internet Gateway Routing Protocol. A proprietary interior gateway protocol used to exchange routing information between Cisco Systems routers.
IHV
Independent Hardware Vendor. A company that manufactures hardware related to computers such as accessories or components, but not complete systems.
IIOP
Internet Inter-ORB Protocol. A protocol based on Common Object Request Broker Architecture (CORBA), which defines how distributed objects communicate and allows client software on many platforms to access and use the same object on a server. See ORB (Object Request Broker).
IIS
(Internet Information Server). Microsoft’s Web server software, which uses Hypertext Transfer Protocol (HTTP) to deliver World Wide Web documents. It provides functions for security, Gopher and FTP servers, and CGI.
ILEC
Incumbent Local Exchange Carrier. A telephone company providing local telephone service to its customers. Compare with CLEC.
ill-behaved
Programs called ill-behaved are designed to bypass normal operating system functions, which may result in better performance but makes the program less portable and more likely to be restricted to specific hardware. See well-behaved.
illustration program
A program used for drawing illustrations. Illustration programs store images in vector graphics format. Examples are Adobe Illustrator and Macromedia Freehand (for Macintosh and Windows), and CorelDRAW for Windows.
IM
Instant Messaging. A live chat and email service that enables you to find your friends when they are online and send messages or talk via a private chat room. Each user has a private list of instant messaging addresses, and the instant messaging system can be set to alert you when someone on your list is online. You can leave an email message for a user who is not available online. Examples of instant messaging systems are ICQ, Yahoo! Pager, AOL Instant Messenger, Ding!, PeopleLink, and talk.com; some of these are available for free download. Since there is no standard for instant messaging, anyone you communicate with must use the same system you use.
iMac
(internet Macintosh). A Macintosh designed for easy access to the Internet, in a futuristic translucent case. The iMac includes a 233MHz PowerPC G3 processor, 32MB SDRAM, 4GB hard disk drive, 24x CD-ROM drive, built-in 56K modem, 10/100Base-Tx Ethernet, built-in 12Mbps Universal Serial Bus ports, Mac OS 8.1, and a collection of software. In addition to Ethernet, which can link iMac to printers and other computers, the iMac has 12Mbps Universal Serial Bus ports for printers, disk drives, scanners, cameras, game controllers, and other peripherals.
IMACS
Image Management And Communication System.
image
A picture. Images on the computer are usually represented as bitmaps (raster graphics) or vector graphics.
image editing
Making changes in an image. Image editing tools allow filtering, color changes, pixel-by-pixel editing to smooth jagged lines, and many special effects such as reversing or digitizing the image.
image editor
A program that can be used to make changes in computer graphics. The program can be used to crop, enhance, paint, and filter scanned images. Adobe Photoshop is an example of an image editing tool. Some page layout programs such as Quark and Pagemaker allow image editing after the image has been imported.
image filter
A tool for modifying images in paint and photo editing programs. Image filters can be used to adjust brightness and contrast, add textures, and create other special effects by changing the color and shading of pixels.
image format
A format in which an image can be stored and used. Some formats, such as TIFF and PICT, can be imported into many different programs and transferred between different platforms. GIF and JPEG are formats used for images on HTML pages. There are image conversion tools in some programs (for example, Photoshop), which make it possible to change from one format to another.
image map
A map or other graphic in an HTML document that has “hot spots” or hyperlinks. When using an interactive browser such as Netscape, a user can click on a spot on the image and bring up a page with more information. For example, clicking a spot on a weather map might open a page with weather forecasts for that region.
image preview
Before WYSIWYG arrived with desktop publishing, a typesetter would have to print out a page to see how it was going to look. Technological improvements brought image preview, which allowed the operator to switch to a screen view of the page, then switch back to the page to edit it. Some word processing and graphics programs still work this way, somewhere between blind page design and full WYSIWYG. Since the advent of windowing technology, the preview image may appear in a separate window which can be viewed at the same time as the page, but not edited.
imagesetter
A high-quality output device, also called a typesetter, which can transfer text and graphics to a page. An imagesetter can accept input from a computer and produce high-resolution copy. Output of the imagesetter is on film-based paper or the actual film which is used to make plates for printing.
imaging
The production of images by photography, filming, videotaping, or scanning. Imaging often means not only preserving an image, but putting it into a form readable by a computer.
IMAP
Internet Message Access Protocol. A protocol that allows a user to perform certain electronic mail functions on a remote server rather than on a local computer. Through IMAP the user can create, delete, or rename mailboxes; get new messages; delete messages; and perform search functions on mail. A separate protocol is required for sending mail. Also called Internet Mail Access Protocol.
IMer
A user of instant messaging (IM).
IMP
Interface Message Processor. A name that was used for the nodes in the original Arpanet.
impact printer
A printer that prints by mechanical impact; for example, a daisy wheel or dot matrix printer. The print head strikes an inked ribbon which puts the images of the characters on the paper.
import
To convert a file from one system or application to the format
of the system or application being used.
IMS
Instructional Management Systems. Educom's Instructional Management Systems Project (IMS) has released technical specifications defining how learning materials will be exchanged over the Internet, and how organizations and individual learners will use them. The goal is the adoption of a set of open standards for Internet-based education. IMS Metadata will be represented in XML/RDF format.
IMS
Information Management System. A database management system for mainframes from IBM.
IMTV
Interactive Multimedia TeleVision.
IN
INput.
incompatible
Not able to work together. Can be said of hardware/hardware, software/software, or hardware/software combinations.
incremental backup
Making a copy of only the files that have changed since the last backup, instead of backing up every file. Incremental backup saves a lot of time and can save storage space.
indefinite iteration
Repeating a series of instructions an indefinite number of times until a specific condition is met; for example, performing a search until the item has been found or determined not to be there.
indent
Aligning a portion of text farther inside of the margin than the surrounding text. The first line of a paragraph is often indented from the left margin. In extracts, a whole section of text may be indented from right and left margins.
Indeo video
A way of recording, compressing, and decompressing video for playing on a computer. The software is from Intel; one of its main applications is video conferencing.
independent hardware vendor
(IHV). A company that manufactures hardware related to computers such as accessories or components, but not complete systems.
independent software vendor
(ISV). A company that specializes in the development and sale of software.
indicator light
A little light on a computer or peripheral, usually an LED, which indicates the device is on, a drive is active, or other information.
1. A property of an electric circuit that causes an electromotive force to be induced in it by a variation of current either in the circuit itself or in a neighboring circuit. 2. The measure of inductance, which is the ratio of induced electromotive force to the rate of change of the inducing current.
Industrial Robot Language
(IRL). A high-level language used for the programming of industrial robots.
Industry Standard Architecture
(ISA). A PC expansion bus used for modems, video displays, speakers, and other peripherals. PCs with ISA commonly have some 8-bit and some 16-bit expansion slots.
inews
A UNIX program used to post Usenet articles.
inference
A process of deriving new facts from facts already known, by means of the rules of logic.
inference rule
A logical rule used to make inferences (derive new facts from facts already known).
infinite loop
A program loop that repeats itself forever, unless interrupted from outside the program. An infinite loop can be caused by a bug in the program, or may be intentional, as with a screen saver that repeats itself until the user interrupts it by touching the mouse or keyboard.
info
Top-level newsgroup category for a University of Illinois newsgroup.
Info Strada
Another name for the information superhighway. (“Strada” is Italian for road or highway).
Infobahn
The Information Superhighway. The expression comes from the German Autobahn, a superhighway for automobiles.
infopreneur
An entrepreneur in the information industry; a provider of information, usually through electronic media.
Information and Content Exchange
(ICE). A protocol based on XML which will make it easier for large businesses and organizations to manage and exchange information and assets via networks, using secure transactions. ICE can be used by syndicated publishing networks, Web superstores, and online resellers to automate many transactions and reduce the cost of doing business online.
information engineering
(IE). The methods and technologies used to process information within an organization.
Information Management System
(IMS). A database management system for mainframes from IBM.
information packet
A packet of data which can be sent over a network.
Information Processing Techniques Office
(IPTO). The agency formed by the Department of Defense (DoD) in 1962 to coordinate ARPA's command and control research. Later it became ISTO.
Information Products Interchange
(IPI). A working committee of the Telecommunications Industry Forum whose job it is to establish standards and guidelines for the telecommunications industry. The IPI has worked on Telecommunications Interchange Markup (TIM) and Telecommunications Electronic Document Delivery (TEDD).
Information Resource Management
(IRM). The management of information resources in a large business enterprise or other organization.
Information Science and Technology Offic
(ISTO). An agency formed by the DoD in 1986 as an expansion of Information Processing Techniques Office (IPTO). See also CSTO.
information service
An online service such as CompuServe, Prodigy, or America Online that provides access to many kinds of information.
information superhighway
A name first used by U.S. Vice President Al Gore for the vision of a global, high-speed communications network that will carry voice, data, video, and other forms of information all over the world, and that will make it possible for people to send email, get up-to-the-minute news, and access business, government and educational information. The Internet is already providing many of these features, via telephone networks, cable TV services, online service providers, and satellites.
Information Technology
(IT). The technology of data processing/information management.
information warfare
An attack on vital computer systems that control security, emergency response, financial transactions, transportation, communications, etc.
Infoseek
An Internet search engine (http://www.infoseek.com/).
INIT
Initialize.
ink cartridge
The cartridge that supplies ink for an inkjet printer.
inkjet printer
A printer in which the image is made by tiny ink droplets which are sprayed from a nozzle onto a piece of paper. Inkjet printers can produce high-resolution color or black and white images.
inline graphic
A built-in graphic image that is displayed by the browser as part of an HTML document and is retrieved along with it, not requiring a separate viewer.
inline image
A built-in graphic image that is displayed by a browser as part of a document written in HTML, and is retrieved along with it, not requiring a separate viewer.
inline video
A video clip which is embedded on a web page; inline video runs in real time and does not require a separate player.
input
To enter data into a computer; or, the data that is input.
input device
A peripheral device that is used to enter commands or information into a computer, such as a keyboard, mouse, joystick, modem, scanner, or touch screen.
input devices
Peripheral devices that are used to enter commands or information into a computer, such as the keyboard, mouse, joystick, modem, scanner, and touch screen.
input focus
The area of a window where the user can input data by means of the keyboard or mouse.
input/output
(I/O). Transfer of data into a computer, and from the computer to the outside world.
Ins key
Insert key. A key that is used to switch between insert and typeover modes.
insert key
(Ins). A key that is used to switch between insert and typeover modes.
insert mode
A mode in which characters typed will be inserted where the cursor is on the screen, moving aside type already on the line. See typeover mode and overwrite mode.
instant messaging
(IM). A live chat and email service that enables you to find your friends when they are online and send messages or talk via a private chat room. Each user has a private list of instant messaging addresses, and the instant messaging system can be set to alert you when someone on your list is online. You can leave an email message for a user who is not available online. Examples of instant messaging systems are ICQ, Yahoo! Pager, AOL Instant Messenger, Ding!, PeopleLink, and talk.com; some of these are available for free download. Since there is no standard for instant messaging, anyone you communicate with must use the same system you use.
instant print
A mode in which a computer is used like a typewriter. Each character prints as it is struck.
Institute for Certification of Computer
(ICCP). An organization in Des Plaines, IL, U.S.A. that certifies computer professionals in many countries. Certification is given on the basis of tests, academic credit, and/or job experience. The different types of certification are: Associate Computer Professional (ACP), Certified Computer Programmer (CCP), Certified Data Processor (CDP), and Certified Systems Professional (CSP).
Institute for Global Communications
(IGC). An organization dedicated to using computer networks to further the causes of peace, human rights, and preserving the environment. The IGC promotes the use of high technology to improve international communication and information exchange. IGC networks include PeaceNet, EcoNet, ConflictNet and LaborNet.
Institute of Electrical and Electronics
(IEEE). A worldwide professional association for electrical and electronics engineers, which sets standards for telecommunications and computing applications.
instruction
A statement that indicates an operation for the computer to perform and any data to be used in performing the operation. An instruction can be in machine language or a programming language.
instruction cycle
Each time a computer is given an instruction in machine language, the CPU must complete a cycle of four steps: fetch the instruction from main memory, decode it, execute it, and store the result. These four steps are the instruction cycle; the term also refers to the length of time one cycle takes.
instruction time
The first half of the instruction cycle, in which the instruction is fetched from memory, transferred to the instruction register, and decoded.
Instructional Management Systems
(IMS). Educom's Instructional Management Systems Project (IMS) has released technical specifications defining how learning materials will be exchanged over the Internet, and how organizations and individual learners will use them. The goal is the adoption of a set of open standards for Internet-based education. IMS Metadata will be represented in XML/RDF format.
insulator
A material that does not conduct electrical current.
INTAP
Interoperability Technology Association for Information Processing. A technical organization involved in developing Japanese OSI profiles and conformance tests.
integer
A whole number. A positive or negative number with no fractional part; a fixed-point number in which the part after the decimal is zero.
Integer BASIC
A version of BASIC written for the Apple II that only uses integers in calculations.
integrated circuit
(IC). Also called microelectronics or chips. An integrated circuit is a microelectronic device comprising many miniature transistors and other electronic components on a single thin rectangle of silicon or sapphire, approximately 1/16″ to 5/8″ on a side, and 1/30″ thick. An integrated circuit can contain dozens, hundreds, or millions of electronic components. To make a chip, impurities are added to the supporting material, or substrate, in specific places to create P-type and N-type regions; then by projecting light onto light-sensitive chemicals, polysilicon or aluminium tracks are etched into the top 1/1000″ of the substrate to make the electronic circuits. Chips come in analog, digital and hybrid types. Compared with earlier technology, microelectronics are faster, more compact, more energy-efficient, and cheaper to manufacture. The most complete integrated circuit is a microprocessor.
http://www.intel.com.
intelligent agent
A software routine that uses intelligence to do an assigned task; for example, searching through incoming mail and reserving items related to a certain subject.
intelligent character recognition
(ICR). The ability of a computer to recognize hand-printed characters or typeset characters that are unclear.
intelligent hub
A central connecting device in a network that provides intelligent functions as well as forwarding signals. An intelligent hub can provide bridging, routing and switching, and even more complex functions such as network management and LAN emulation. See also active hub, passive hub.
intelligent modem
A modem that has a command state in which it can be programmed, and an online state in which it performs automatic functions such as dialing, answering the phone, handshaking, and transmitting and receiving communications. The first intelligent modem was the Hayes Smartmodem from Hayes Microcomputer Products, Inc. The commands used by Hayes modems became an industry standard and are now used by many other modems.
intelligent terminal
A terminal that is part of a larger system and uses a main computer for storage of data, but has its own processing capability.
Inter Application Communications
(IAC). A technology introduced with the Macintosh System 7 which enables applications to communicate with each other when necessary carry out commands given by the user. Drag and drop is one function that makes use of IAC.
inter-
A prefix meaning between or among; for example, an internet is a network between networks.
inter-packet gap
A time delay which is required between data packets on an Ethernet so that all connected machines have a chance to transmit. Ethernet nodes must wait for the network to be idle before sending data.
Inter-Process Communication
(IPC). The automatic exchange of data between one process and another, within a computer or between networked computers. Examples are Unix sockets, Windows Dynamic Data Exchange, and Macintosh InterApplication Communications.
interactive
A term for computer programs that accept input from the user while they are running; for example, a game that waits for the user to take an action, then responds to that action. The interaction between computer and user may take place through typed commands, voice commands, mouse clicks, or other means of interfacing. The opposite of interactive processing is batch processing, where all the commands are given before the program starts to run.
Interactive CourseWare
(ICW) A U.S. military term for software used with computer-aided instruction and computer-based training. Interactive CourseWare relies on interaction with the trainee to determine the pacing and sequence of a course of instruction.
interactive development environment
(IDE). A set of programming tools (such as Visual C++ or Visual Basic) that help the user to write software.
interactive processing
In interactive processing, the user communicates with the computer while the program is running, perhaps giving instructions for each item. In batch processing, a whole series of instructions are executed without stopping for input from the user.
interactive session
A work session in which there is an exchange of communication between the user and the computer.
interactive TV
A kind of television that allows interactive participation by the viewer; for example, shop-at-home or movies on demand.
interactive video
(IV). Video in which the user can control which part of a program to view, or interact with certain parts of the program.
interface
A shared boundary where two or more systems meet; or the means by which communication is achieved at this boundary. An interface can be between hardware and hardware (such as sockets and plugs, or electrical signals), hardware and software, software and software, human and computer (such as a mouse or keyboard and display screen).
interface adapter
A device that connects a computer or computer terminal to a network.
interface analysis
Using a software test to check the interfaces between program elements to see if they are consistent and properly designed.
Interface Message Processor
(IMP). A name that was used for the nodes in the original Arpanet.
Intergraph Computer Systems
(ICS). A Huntsville, Alabama computer manufacturer. Intergraph develops, manufactures, sells, and supports computer systems for the Technical Desktop. Some products are Intel-based TD personal workstations, TDZ 3D workstations, servers, peripherals, and interactive computer graphics systems.
Interior Gateway Protocol
(IGP). An Internet protocol which provides routing information to the routers within an autonomous network.
interlaced display
A display technology in which electron beams scan alternately all the even numbered lines then all the odd numbered lines, so that the whole screen is covered in two vertical scans.
interleave
To arrange parts of one sequence of data so they alternate with parts of another sequence of the same type of data. Audio, images, or text may be stored in alternating segments this way. When a file is retrieved, the system puts the right segments back together again. Interleaving makes more efficient storage.
interleaving
Alternating parts of one stream of data with parts of another stream of data in order to store the data more efficiently.
intermediate system
In OSI terminology, a system which is between and serves instead to relay communications between end systems.
Intermediate System to Intermediate Syst
(IS-IS). The OSI protocol which allows intermediate systems to exchange routing information.
intermittent error
An error that occurs from time to time, but not predictably.
internal bus
A bus connecting components that are very close to each other, such as main memory and the central processing unit.
internal drive
A drive which is inside the computer case.
internal font
A font that is built into the printer.
internal interrupt
An interrupt caused by a machine instruction; for example, a need for input or output, a call for a subroutine, or certain errors.
internal modem
A modem that is inside the computer, connected by plugging into an expansion slot.
Internal Organization of the Network Lay
(IONL). The OSI standard for the detailed architecture of its Network Layer, which divides it into subnetworks and defines the protocols that connect them.
internal unit
A unit which is inside the computer; for example, a built-in CD-ROM drive or modem.
International Business Machines Corporat
(IBM). International Business Machines Corporation, Armonk, NY. The world's largest computer company, begun in New York in 1911 as the Computing-
Tabulating-Recording Company and renamed IBM in 1924. IBM sold
tabulating machines and punch cards from the 1920s through the 1960s, and started selling computers in 1953. IBM sells mainframes, minicomputers, workstations, personal computers, and software, including the OS/2 operating system. In 1991, IBM joined with Apple Computer and Motorola to produce the PowerPC chip.
International Data Corporation
(IDC). A Framingham, Massachusetts company that does market research and analysis on all aspects of information technology.
International Electrotechnical Commissio
(IEC). An organization in Geneva that sets international standards for the electrical and electronics fields. IEC created the Joint Technical Committee for information technology with ISO.
International Federation for Information
(IFIP). An international federation of professional and technical organizations in Geneva, Switzerland, concerned with information processing. There is one representative organization from each country; the United States representative is FOCUS. IFIP does research to help develop standards, and advises the International Telecommunications Union.
International Organization for Standardi
(ISO). A voluntary organization founded in 1946, comprised of the national standards organizations of many countries, and responsible for creating international standards in many areas, including computers and communications. ANSI (American National Standards Institute) is the American member of ISO. ISO produced OSI (Open Systems Interconnection), a seven-layer model for network architecture.
International Phonetic Alphabet
(IPA). An alphabet designed as a pronunciation guide for all languages, which represents each sound in human speech with its own symbol.
International Standard
The series of standards created by the International Organization for Standardization (ISO).
International Telecommunications Union
(ITU). An organization in Geneva, Switzerland. ITU is one of the organizations working on forming international standards for communication. ITU-T is the arm of ITU responsible for telecommunications standards.
International Time Recording Company
A New York time-clock company that merged with other companies in 1911 to form the Computing-Tabulating-Recording Company, which in 1924 was renamed the International Business Machines Company (IBM).
internationalization
Designing an operating system so the user interface can be adapted to different languages and measurement systems for users of different nationalities. Contrast with localization.
Internaut
A person who navigates the Internet.
internet
Short for internetwork. A network of networks; a group of networks interconnected via routers. Contrast with The Internet (with a capital I), the world's largest internet.
Internet
The biggest internet in the world. This worldwide information highway is comprised of thousands of interconnected computer networks, and reaches millions of people in many different countries. The Internet was originally developed for the United States military, and then became used for government, academic and commercial research and communications. The Internet is made up of large backbone networks (such as MILNET, NSFNET, and CREN), and smaller networks that link to them. The U.S. National Science Foundation maintains a major part of the backbone (NSFNET). The Internet functions as a gateway for electronic mail between various networks and online services. The World Wide Web facility on the Internet makes possible almost instantaneous exchange of information by linking documents around the world. Internet computers use the TCP/IP (Transmission Control Protocol/Internet Protocol). There are over six million hosts on the Internet: mainframes, minicomputers or workstations that support the Internet Protocol. The Internet is connected to computer networks worldwide that use various message formats and protocols; gateways convert these formats between networks so that the Internet functions as one big network. UNIX utilities such as FTP, Archie, Telnet, Gopher and Veronica have been widely used to access the Internet. The Internet sometimes appears to be amorphous and unregulated, but there are several administrative bodies: the Internet Architecture Board, which oversees technology and standards; the Internet Assigned Numbers Authority, which assigns numbers for ports and sockets, etc.; InterNIC, which assigns Internet addresses; the Internet Engineering and Planning Group, Internet Engineering Steering Group, and the Internet Society.
Internet access
Access to the Internet via a dial-up account or direct connection.
Internet Access Provider
(IAP). An organization or company which provides Internet access to individuals, businesses, or other groups. An IAP may provide leased line services for dedicated high-speed access, and dial-up accounts that use a modem and a regular telephone line. Major online services such as America Online and CompuServe often are also Internet access providers.
Internet account
An account with an Internet Service Provider, usually for a monthly fee, that provides Internet access.
internet address
An IP address that identifies a specific computer or terminal on an internet. (The lowercase “i” in internet means a small computer network, rather than the Internet).
Internet address
A 32-bit address assigned to hosts using TCP/IP, given in dotted decimal notation; for example, 115.332.4.3.
Internet appliance
A hand-held computer designed only for Internet use.
Internet Architecture Board
(IAB). Formerly Internet Activities Board. The technical body that governs the Internet. It has two task forces: the Internet Research Task Force (IRTF), which explores new technologies, and the Internet Engineering Task Force (IETF), which develops standards.
Internet Assigned Numbers Authority
(IANA). The authority responsible for assigning numbers (such as port or socket numbers) in the Internet Suite of Protocols. For number assignments, email [email protected]
Internet Control Message Protocol
(ICMP). An extension to the Internet Protocol which is used to communicate between a gateway and a source host, to manage errors and generate control messages.
Internet Engineering Steering Group
(IESG). Executive committee of the Internet Engineering Task Force.
Internet Engineering Task Force
(IETF). One of the task forces of the Internet Activities Board. The IETF is responsible for short-term engineering needs of the Internet and specifying new standards.
Internet Explorer
A graphical World-Wide Web browser from Microsoft for Microsoft Windows, Windows 95, Windows NT, and Macintosh. It can be downloaded from the Internet.
Internet gateway
A system for converting messages between TCP/IP and other protocols. Through Internet gateways, all the various networks in the world become one big network.
Internet Gateway Routing Protocol
(IGRP). A proprietary interior gateway protocol used to exchange routing information between Cisco Systems routers.
Internet Information Server
(IIS). Microsoft's Web server software, which uses Hypertext Transfer Protocol (HTTP) to deliver World Wide Web documents. It provides functions for security, Gopher and FTP servers, and CGI.
Internet Inter-ORB Protocol
(IIOP). A protocol based on Common Object Request Broker Architecture (CORBA), which defines how distributed objects communicate and allows client software on many platforms to access and use the same object on a server. See ORB (Object Request Broker).
Internet Message Access Protocol
(IMAP). A protocol that allows a user to perform certain electronic mail functions on a remote server rather than on a local computer. Through IMAP the user can create, delete, or rename mailboxes; get new messages; delete messages; and perform search functions on mail. A separate protocol is required for sending mail.
Internet Message Support Protocol
(IMSP) An Internet protocol that allows mail preferences and address books to be stored on a remote server. And IMSP allows users who use e-mail from multiple locations to have access to and maintain a single address book. IMSP is now referred to as Application Configuration Access Protocol (ACAP).
Internet Network Information Center
InterNIC. A group of three organizations which together provide services for NSFNet. General Atomics handles information services, AT&T handles directory and database services, and Network Solutions, Inc. (NSI) handles registration services. Network addresses and domain names for the Internet are assigned by InterNIC through NSI.
Internet PC
A specially-designed computer that is only for surfing the Internet.
Internet phone
Technology for sending real-time voice communication over the Internet.
Internet Protocol
(IP). The IP part of TCP/IP; the protocol used to route a data packet from its source to its destination over the Internet.
Internet Public Library
(IPL). An online public library sponsored by University of Michigan School of Information and Library Studies (http://ipl.sils.umich.edu/). The library offers a reference department, a youth department, a professional staff who will answer questions, and many other services.
Internet Registry
(IR). A service provided by the Defense Data Network's Network Information Center, which has the responsibility of handling network address and Autonomous System identifiers for the Internet Assigned Numbers Authority (IANA).
Internet Relay Chat
(IRC). Worldwide real-time conferencing on the Internet, reached by Telnetting to an IRC server. There are hundreds of IRC channels for many different subjects, from many countries. There are purely social chat rooms, and channels dedicated to more serious purposes.
Internet Research Task Force
(IRTF). One of the task forces of the Internet Architecture Board; responsible for research and development of the Internet Protocol. The IRTF explores new technologies and makes recommendations to the Internet Engineering Task Force (IETF).
Internet Service Provider
(ISP). A company which provides Internet access or Internet accounts to individuals, businesses, and other groups.
Internet Society
(ISOC). A non-profit, professional membership organization in Reston, Virginia, U.S.A., which is dedicated to educating people about the Internet, and encouraging computer networks to voluntarily join in creating a worldwide communications and information infrastructure. The ISOC supports the development of technical standards through the IAB, IETF and IRTF.
Internet Talk Radio
(ITR). Audio news files from the National Press Building, Washington, DC; available by FTP.
Internet utility
A program for searching the Internet. Some examples: Archie searches FTP sites; Veronica searches Gopher sites; Jughead searches Gopher directories; WAIS searches the complete contents of documents.
Internet Video Phone
An application from Intel that lets you talk to others across the Internet using both audio and video.
Internet Worm
A computer worm that in November 1988 infected over 6,000 computers on the Internet via the Sun UNIX sendmail program and other security loopholes.
internetwork
1. A wide area network that connects smaller networks. 2. To pass from one network to another.
Internetwork Packet Exchange
(IPX). A Novell NetWare protocol for delivering messages in datagram format.
internetworking
Communicating between two or more networks via a router or gateway.
InterNIC
Internet Network Information Center. A group of three organizations which together provide services for NSFNet. General Atomics handles information services, AT&T handles directory and database services, and Network Solutions, Inc. (NSI) handles registration services. Network addresses and domain names for the Internet are assigned by InterNIC through NSI.
interoperability
The ability of software and hardware on different machines to communicate with each other.
Interoperability Technology Association
(INTAP). A technical organization involved in developing Japanese OSI profiles and conformance tests.
interoperable
A word describing systems that can communicate or work with each other.
interoperable database
A database front-end which communicates with other databases of different formats so that they all work together, and data from one system can be accessed from another system.
interpolated resolution
The resolution a device can generate by using a process known as interpolation — estimating intermediate values based on the knowledge of two known values in a sequence.
interpret
To run a program from source code by reading it one line at a time and performing each instruction immediately.
interpreter
A program which executes source code by reading it one line at a time and performing each instruction immediately. An interpreter is different from a compiler, which does not execute the source code, but translates it into object code (machine language) which is stored in a file and executed later. Some programming languages must be interpreted; some can be both interpreted and compiled.
interpretive language
A programming language that must be interpreted. Programs written in these languages can only be run if the interpreter is available in the computer.
interpupillary distance
(IPD).The distance between the eyes; a measurement used in designing virtual reality devices such as head mounted displays.
interrecord gap
(IRG). The space between blocks of data on a magnetic tape.
interrupt
A temporary suspension of a process. There are two main sources of interrupts: a signal from outside the computer, such as someone touching the keyboard or mouse (a hardware interrupt); or a machine instruction such as a request for input or output (a software interrupt). When an interrupt occurs, the CPU may temporarily gives control to an interrupt handler routine. The suspended process is resumed after the interrupt has been handled.
interrupt handler
A routine that is called to deal with an interrupt.
interrupt priority
The relative importance of an interrupt. If two interrupts occur at once, the higher priority one gets handled first.
Interrupt Request
1. (IRQ). Designation of a hardware interrupt in a PC. A PC has either 8 or 16 lines which accept interrupts from attached devices (such as a keyboard, SCSI card, scanner, sound card, mouse, etc.). Different devices competing for the same IRQ cause conflicts. The Plug and Play system was designed to simplify everything through resource arbitration: the operating system keeps track of which resources are allocated to which device. 2. (IR). In the IBM 8100 Information System, a request which establishes the interrupt priority of a particular process.
Interrupt Service Routine
(ISR). A software routine that is activated to respond to an interrupt.
intersect
1. To meet and cross at a point; as the intersection of two lines. 2. To compare two database files and derive a third file with records that are found in both.
InterSLIP
A freeware Serial Line Internet Protocol for Macintosh from Intercon Systems Corporation.
intra-
A prefix meaning within; for example, an intranet is a network within a building or organization.
intranet
A local area network which may not be connected to the Internet, but which has some similar functions. Some organizations set up World Wide Web servers on their own internal networks so employees have access to the organization's Web documents.
intrusive testing
Testing in which the behavior of the software being tested may be changed from its normal behavior by the test itself.
Invalid directory
A DOS error message that means the requested directory does not exist.
invitation to send
(ITS). A character sequence sent to a teletypewriter terminal to see if it is ready to transmit data. The term originated at Western Union.
IOBench
A UNIX benchmark that measures I/O throughput and fixed workload.
IOCall
A UNIX benchmark that measures OS performance and system call interface efficiency.
IOgen
A UNIX benchmark written by Symbios Logic. The program displays as output the number of processes doing input/output, the average response time, the number of I/O operations per second, and the number of kilobytes per second.
IOmeter
Formerly called Galileo. A benchmark written by Intel to measure I/O for single and clustered systems. IOmeter tests a computer's I/O subsystem performance under a controlled load.
IONL
Internal Organization of the Network Layer. The OSI standard for the detailed architecture of its Network Layer, which divides it into subnetworks and defines the protocols that connect them.
IOstone
A multi-platform disk benchmark program that measures file I/O and buffer cache efficiency. This benchmark was originally created for UNIX and later ported to OS/2 and DOS.
IOzone
A benchmark that measures the number of bytes per second that a system can read or write to a file. It can be used with DOS, SCO, Linux, Solaris, and BSDI.
IP
1. Internet Protocol. The IP part of TCP/IP; the protocol that is used to route a data packet from its source to its destination over the Internet. 2. Intellectual Property
IP address
The Internet Protocol address; a numeric address such as 123.231.32.2 that the domain name server translates into a domain name.
IP datagram
The basic unit of information transmitted via the Internet. A datagram has the addresses of its source and destination, the data being sent, error checking, and some other fields that define the length of the datagram, whether the datagram is or can be fragmented, etc.
IPA
International Phonetic Alphabet. An alphabet designed as a pronunciation guide for all languages, which represents each sound in human speech with its own symbol.
IPC
Inter-Process Communication. The automatic exchange of data between one process and another, within a computer or between networked computers. Examples are Unix sockets, Windows Dynamic Data Exchange, and Macintosh InterApplication Communications.
IPD
Interpupillary Distance.The distance between the eyes; a measurement used in designing virtual reality devices such as head mounted displays.
IPI
Information Products Interchange. A working committee of the Telecommunications Industry Forum whose job it is to establish standards and guidelines for the telecommunications industry. The IPI has worked on Telecommunications Interchange Markup (TIM) and Telecommunications Electronic Document Delivery (TEDD).
IPL
Internet Public Library. An online public library sponsored by University of Michigan School of Information and Library Studies (http://ipl.sils.umich.edu/). The library offers a reference department, a youth department, a professional staff who will answer questions, and many other services.
IPng
IP Next Generation. The new version of the Internet Protocol (IP) defined by the Internet Engineering Task Force, which has better security and increases Internet addresses from four to 16 bytes, to cope with the explosive growth of the Internet. Also called IPv6.
ips
Inches per second, a measurement of tape speed.
IPSE
Integrated Project Support Environment. An integrated set of technical and management tools which support software development.
IPTO
Information Processing Techniques Office. The agency formed by the Department of Defense (DoD) in 1962 to coordinate ARPA's command and control research. Later it became ISTO.
IPv6
Internet Protocol Version Six. Also known as IPng. The new version of the Internet Protocol (IP) defined by the Internet Engineering Task Force, which has better security and increases Internet addresses from four to 16 bytes, to cope with the explosive growth of the Internet. Also called IPng.
IPX
Internetwork Packet Exchange. A Novell NetWare protocol for delivering messages in datagram format.
IPX/SPX
Internet Packet Exchange/Sequenced Packet Exchange. IPX is a Novell communications protocol used by NetWare clients and servers to deliver messages within and between networks. SPX ensures reliable delivery of complete messages.
IQL
Incoming Quality Level.
IR
1. Internet Registry. A service provided by the Defense Data Network's Network Information Center, which has the responsibility of handling network address and Autonomous System identifiers for the Internet Assigned Numbers Authority (IANA). 2. (IR). In the IBM 8100 Information System, a request which establishes the interrupt priority of a particular process.
IRC
Internet Relay Chat. Worldwide real-time conferencing on the Internet, reached by Telnetting to an IRC server. There are hundreds of IRC channels for many different subjects, from many countries. There are purely social chat rooms, and channels dedicated to more serious purposes.
IRG
(Interrecord Gap). The space between blocks of data on a magnetic tape.
IRM
Information Resource Management. The management of information resources in a large business enterprise or other organization.
iron oxide
A chemical compound made of oxygen and iron; used to coat the surfaces of magnetic tapes and disks.
IRQ
Interrupt Request. Designation of a hardware interrupt in a PC. A PC has either 8 or 16 lines which accept interrupts from attached devices (such as a keyboard, SCSI card, scanner, sound card, mouse, etc.). Different devices competing for the same IRQ cause conflicts. The Plug and Play system was designed to simplify everything through resource arbitration: the operating system keeps track of which resources are allocated to which device.
irrational number
A real number which is not a ratio of two integers; for example, pi and the square root of two. An irrational number can be expressed as an infinite decimal in which not set of consecutive digits repeats itself infinitely.
IRTF
Internet Research Task Force. One of the task forces of the Internet Architecture Board; responsible for research and development of the Internet Protocol. The IRTF explores new technologies and makes recommendations to the Internet Engineering Task Force (IETF).
IS-IS
Intermediate System to Intermediate System Protocol. The OSI protocol which allows intermediate systems to exchange routing information.
ISA
Industry Standard Architecture. A PC expansion bus used for modems, video displays, speakers, and other peripherals. PCs with ISA commonly have some 8-bit and some 16-bit expansion slots.
ISA bus
Industry Standard Architecture bus. A PC expansion bus used for modems, video displays, speakers, and other peripherals. PCs with ISA commonly have some 8-bit and some 16-bit expansion slots.
ISA slot
Industry Standard Architecture slot. An expansion slot that can accommodate ISA-compatible expansion boards.
ISA slots
Industry Standard Architecture slots. Expansion slots that can accommodate ISA-compatible expansion boards.
ISDN
Integrated Services Digital Network. Digital telecommunications lines that can transmit both voice and digital network services up to 128K, and are much faster and more reliable than high-speed analog modems. ISDN lines are offered by many telephone companies.
ISDN adapter
A device that connects a computer to an ISDN channel. It is used instead of a modem, and is either an external unit or a plug-in adapter card. Some ISDN adapters have the ability to automatically switch between analog and digital modes.
ISDN terminal adapter
(TA). A device that connects a computer to an ISDN channel. It is used instead of a modem, and is either an external unit or a plug-in adapter card. Some terminal adapters have the ability to automatically switch between analog and digital modes.
ISO
International Organization for Standardization. A voluntary organization founded in 1946, comprised of the national standards organizations of many countries, and responsible for creating international standards in many areas, including computers and communications. ANSI (American National Standards Institute) is the American member of ISO. ISO produced OSI (Open Systems Interconnection), a seven-layer model for network architecture.
ISO 10646
A character set using 16-bit character codes, also called Universal Character Set (UCS). ISO 10646 is a standard defined by the International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC), and allows 65,536 (or 256 x 256) characters instead of the 256 available in ASCII. If a printer has the UCS feature, it can use a variety of character arrays. The 8-bit character sets ASCII and ISO Latin 1 are subsets within ISO 10646.
ISO 9660
The physical format for CD-ROM discs (including size, tracking, contents of sectors, and so forth) is defined by the Red Book. The standard logical format for CD-ROMs (including the volume and file structure) is defined by ISO 9660: Information Processing – Volume and File Structure of CD-ROM for Information Exchange (1988), issued by the International Standards Organization. This format can be used by many different computers.
ISO Development Environment
(ISODE). (Pronounced “eye-so-dee-eee.”) Software for implementing upper layer services of OSI.
ISO IP
The OSI equivalent to the Internet Protocol (IP); the protocol for OSI Connectionless Network Service. Also called Connectionless Network Protocol (CLNP).
ISOC
Internet Society. A non-profit, professional membership organization in Reston, Virginia, U.S.A., which is dedicated to educating people about the Internet, and encouraging computer networks to voluntarily join in creating a worldwide communications and information infrastructure. The ISOC supports the development of technical standards through the IAB, IETF and IRTF.
isochronous
Equal in time or duration; happening at regular intervals.
isochronous transmission
A way of transmitting data in which there is always a whole number of unit intervals between individual characters. Isochronous transmission is used for time-dependent data such as realtime voice and video.
ISODE
ISO Development Environment. (Pronounced “eye-so-dee-eee.”) Software for implementing upper layer services of OSI.
isometric
Having equality of measure.
isometric view
A way of drawing a three-dimensional object without the distortions created by perspective. In a drawing based on true perspective, parallel lines converge in a vanishing point; this is the way objects look to us in real life. An isometric drawing shows that parallel lines in actuality do not converge, and represents the object's real proportions and spatial relationships; the isometric view is most useful for technical drawings.
isotropic
Having properties that are the same when measured in any direction; for example, the velocity of light, transmission speeds, etc.
ISP
Internet Service Provider. A company that provides Internet accounts.
ISR
Interrupt Service Routine. A software routine that is activated to respond to an interrupt.
ISTO
Information Science and Technology Office. An agency formed by the DoD in 1986 as an expansion of Information Processing Techniques Office (IPTO). See also CSTO.
ISV
Independent Software Vendor. A company that specializes in the development and sale of software.
IT
Information Technology. The technology of data processing/information management.
It’s All In The Subject
(IAITS) . IAITS is the only content in the body of an email where the message is contained in the subject line. For example, the subject of the message could be "I want my money back now!" The body of the email would say simply, IAITS.
italics
Type that is slanted to the right and sometimes more scripted than the text font it matches. Italics are used for emphasis. Typeset italics are the equivalent to underlining with a typewriter.
iteration
The process of running a series of instructions over and over until some condition is satisfied. Or, one repetition of the series.
iterative operation
The repetition of an operation with successive combinations of parameters, or the operation itself; automatic sequential operation.
ITR
Internet Talk Radio. Audio news files from the National Press Building, Washington, DC; available by FTP.
ITS
Invitation To Send. A character sequence sent to a teletypewriter terminal to see if it is ready to transmit data. The term originated at Western Union.
ITU
International Telecommunications Union, in Geneva, Switzerland. ITU is one of the organizations working on forming international standards for communication. ITU-T is the arm of ITU responsible for telecommunications standards.
ITU-T
International Telecommunications Union, in Geneva, Switzerland. ITU is one of the organizations working on forming international standards for communication. ITU-T is the arm of ITU responsible for telecommunications standards.
IV
Interactive video. Video in which the user can control which part of a program to view, or interact with certain parts of the program.
J++
Also known as Visual J++, this is a Windows-based Java development system that's used to create Java applications that can run on any platform.
J2EE
Java 2 Platform, Enterprise Edition: a platform from Sun for building distributed enterprise applications by performing services in the middle tier between the user's machine and the enterprise's databases and legacy systems.
jack
A connector into which a plug is inserted.
jack in
To enter a virtual reality simulation by means of a computer. A term which comes from cyberpunk science fiction and originally referred to plugging in electrodes to interface the brain directly with a virtual reality.
jack out
To leave a virtual reality simulation; the opposite of jack in.
jacket
The plastic covering that protects a floppy disk.
JAD
Joint application development is a RAD (Rapid Application Development) concept, which involves cooperation between the designer of a computer system and the end user to develop a system that exactly meets the user's needs.
Jade
A freely-available DSSSL engine developed by James Clark. It is a fast C++ based processor that is available for Win32 and UNIX platforms.
jaggies
The jagged edges that appear in graphics on diagonal or curved lines. The stair-step appearance is the result of trying to build a diagonal or curved line out of little squares. One solution is to create the image in a large format and reduce it to the desired size, so the pixels are smaller in relation to the image. Another solution is anti-aliasing, which means putting pixels along the jagged edge which are of an intermediate color between the background and the image. This makes the line look smoother.
JANET
Joint Academic Network. A university network in the United Kingdom, renamed “Super-JANET” after it upgraded to higher speed links.
Japanese Electronic Industry Development
(JEIDA). A Japanese standards organization.
jargon
The specialized or technical language of a trade; for example, computerese.
Jargon File, The
The Jargon File. A large online collection with definitions of hacker and computing terms (http://beast.cc.emory.edu/Jargon30/JARGON.HTML).
Java
A cross-platform programming language from Sun Microsystems that can be used to create animations and interactive features on World Wide Web pages. Java programs are embedded into HTML documents. HotJava and Netscape Navigator (2.0 or above) are Web browsers that run Java applications.
Java 2
A version of the programming language Java. The files are formated in byte code, and the language runs on most computers. Java is very important for exploring the World Wide Web. See also Java.
Java applet
A little application written in Java language which can be embedded in an HTML document. On the World Wide Web, Java applets can be executed by Netscape Navigator or Sun's HotJava browser.
Java Development Kit
(JDK). A software development kit from JavaSoft, for producing Java programs.
Java Virtual Machine
(JVM). A virtual machine is a simulated computer; it runs on a host computer but behaves as if it is a separate computer. The Java Virtual Machine works as a self-contained operating environment to run Javaapplets, with the advantage that Java applets can be run independently from the host operating system.
JavaScript
A cross-platform WWW scripting language from Netscape Communications, very popular because it is simple and easy to learn. It can be included in an HTML file by using the tag <script language="JavaScript">.
JavaSoft
The division of Sun Microsystems that works with Java technology.
Jaz drive
A compact, removable-cartridge disk drive made by Iomega Corporation. A 540MB and a 1GB cartridge are available.
JBIG
Joint Bi-level Image Experts Group. A group formed by ISO, IEC, and ITU-T for creating a lossless compression standard for images. JBIG compression is highly efficient and gives high-quality images with no loss of data from compression and decompression. It can be used with text, line art, and halftones.
JCL
Job Control Language. A command language for mainframes and minicomputers, used for launching applications.
JDK
Java Development Kit. A software development kit from JavaSoft, for producing Java programs.
JEDEC
Joint Electronic Device Engineering Council. An international organization that sets standards for integrated circuits.
JEIDA
Japanese Electronic Industry Development Association. A Japanese standards organization.
JetForm
Forms software from JetForm Corporation for DOS, Windows and Macintosh.
jewel box
A plastic container for a CD or CD-ROM disc. Also called jewel case.
JFIF
JPEG File Interchange Format.
JIPS
JANET (Joint Academic Network) Internet Protocol Service. See JANET and SuperJanet.
Jmark
A benchmark suite including eleven synthetic Java performance tests.
job
In computer terminology, a project done on a computer.
Job Control Language
(JCL). A command language for mainframes and minicomputers, used for launching applications.
job queue
The lineup of jobs to be run.
job scheduling
Setting up a job queue and scheduling when jobs will be run. This term is most often used with large computers, but can also apply in a shop with small computers.
Jobs, Stephen
Cofounder of Apple Computer in 1975, with Steve Wozniak. Apple released the Macintosh computer in 1984, which was a milestone in the personal computer revolution. In 1985 Jobs started NeXT Inc., a company that builds workstations.
Joe
A computer account whose password is the user's name. Joe accounts are easy for crackers to break into because the passwords are easy to guess.
Joint Academic Network
(JANET). A university network in the United Kingdom, renamed “Super-JANET” after it upgraded to higher speed links.
joint application development
(JAD). is a RAD (Rapid Application Development) concept, which involves cooperation between the designer of a computer system and the end user to develop a system that exactly meets the user's needs.
Joint Bi-level Image Experts Group
(JBIG). A group formed by ISO, IEC, and ITU-T for creating a lossless compression standard for images. JBIG compression is highly efficient and gives high-quality images with no loss of data from compression and decompression. It can be used with text, line art, and halftones.
Joint Electronic Device Engineering Coun
(JEDEC). An international organization that sets standards for integrated circuits.
Joint Photographic Experts Group
(JPEG.) A format for storing high-quality color and grayscale photographs in bitmap form; also the group that developed the format. JPEG provides lossy compression by segmenting the picture into small blocks which are divided to get the desired ratio; the process is reversed to decompress the image. JPEG uses the JPEG File Interchange Format, or JFIF.
Joint Technical Committee
JTC1, created by ISO and IEC. It is comprised of standards organizations from over 75 countries, and is involved with setting standards for information processing.
joule
A unit of work or energy equal to 10,000,000 ergs, or the work done by a force of one newton acting through a distance of one meter. Named for James Joule, English physicist.
journal
A daily, or regular, record of events and transactions.
journaling
Keeping a journal. A journal for a computer includes a record of changes made in files, messages transmitted, etc. It can be used to recover previous versions of a file before updates were made, or to reconstruct the updates if an updated file gets damaged.
journalled file system
A file system in which updates are automatically recorded in a journal, so if the new file is lost it can be recreated.
joystick
A hand held stick like the joystick in an airplane, which is used as a pointing device in arcade games and video games. The joystick can move an object on screen in any direction. It usually has one or more push buttons for shooting, jumping, etc. Joysticks are also used in some CAD systems.
JPEG
Joint Photographic Experts Group. A format for storing high-quality color and grayscale photographs in bitmap form; also the group that developed the format. JPEG provides lossy compression by segmenting the picture into small blocks which are divided to get the desired ratio; the process is reversed to decompress the image. JPEG uses the JPEG File Interchange Format, or JFIF.
JPEG++
An extension to JPEG from Storm Technology that allows different areas of a picture to be compressed at different ratios.
JPEGView
A Mac utility for viewing JPEG and TIFF files.
JSA
Japanese Standards Association.
JTC1
Joint Technical Committee for information technology, created by ISO and IEC. It is comprised of standards organizations from over 75 countries, and is involved with setting standards for information processing.
Jughead
Jonzy's Universal Gopher Hierarchy Excavation And Display. Jughead is a tool which can be used to search for a key word on all levels of a Gopher menu.
jukebox
A machine that holds and plays CDs, vinyl records, videodisks, tape cartridges, or CD-ROMs. The jukebox automatically picks up disk or tape the user has selected, and moves it to the drive to be played.
Julian date
A way of writing a date which shows the year in positions 1 and 2, and the day in positions 3-5. The day is a number from 1 through 366, with zeros in the unused positions. So January 12, 1997 would be 97012.
JUNET
Japan UNIX Network.
justification
Alignment of text on both left and right margins, except for last lines of paragraphs, which are flush left, and paragraph indents if used.
justified
Aligned on the left and right margins, with the last lines of paragraphs flush left. Justified text may have paragraph indents.
JVM
Java Virtual Machine. A virtual machine is a simulated computer; it runs on a host computer but behaves as if it is a separate computer. The Java Virtual Machine works as a self-contained operating environment to run Java applets, with the advantage that Java applets can be run independently from the host operating system.
k
1. Abbreviation for the prefix kilo-, meaning one thousand. 2. Kilobyte. One thousand bytes (103) or 1024 (210) bytes. A unit of measurement used for computer file sizes. 2. Okay (chat).
K
1. A unit of measurement of computer storage capacity, 2^10 or 1024. 2. Kelvin, a unit of thermodynamic temperature.
k12
Top-level newsgroup category for an elementary and secondary education newsgroup.
ka- kichen assistant
a person who asists in the kichen giveing a hand in a task ,and use thier abilities of the job and delivering food or transporting food carts and is below and under an team leader does not have authority over staff , but can make sugestions and can report it to higer up’s in staffing ,and cab help out the team leader. and can try to make under standings for other staff with out the authority.
KA9Q
An implementation of TCP/IP and related protocols for amateur packet radio.
Kaleida Labs, Inc.
A joint project by IBM and Apple Computer for developing multimedia software.
kana
Japanese phonetic writing, which includes the two styles of hiragana and katakana. In Japanese books, kana is mixed with kanji, the whole-word symbols derived from Chinese. On computers, the phonetic symbols of kana are more often used.
kangaroo code
A clumsily-written, disorganized computer program created by a novice.
kanji
A character set of symbols used in Japanese ideographic alphabets. Each character requires 2 bytes to represent it.
katakana
A character set of symbols used in one of the two principal Japanese phonetic alphabets, mainly used for phonetic transliteration of foreign words. Each character uses two bytes.
Katmai New Instructions
(KNI). The code name for MMX2 instructions.
KB
Kilobyte. One thousand bytes (103) or 1024 (210) bytes. A unit of measurement used for computer file sizes.
Kb
1. Kilobit. One thousand bits (103) or 1024 bits (210). A unit of measurement of the capacity of memory integrated circuits. Not to be confused with kilobyte. 2. Sometimes used for kilobyte. One thousand bytes (103) or 1024 (210) bytes. A unit of measurement used for computer file sizes.
Kbit, K-bit, or kbit
Kilobit. One thousand bits (103) or 1024 bits (210). A unit of measurement of the capacity of memory integrated circuits. Not to be confused with kilobyte.
Kbits/sec
Kilobits per second. Thousand bits per second.
KBps
Kilobytes per second. Thousand bytes per second.
Kbps
1. Kilobits per second. Thousand bits per second. A data transfer rate.
Kbs
Kilobits per second. Thousand bits per second.
KBS
Knowledge-Based System. A computer system that is programmed to imitate human problem-solving by means of artificial intelligence and reference to a database of knowledge on a particular subject.
Kbyte or K-byte
Kilobyte. One thousand bytes (103) or 1024 (210) bytes. A unit of measurement used for computer file sizes.
Kbytes/sec
Kilobytes per second. Thousand bytes per second.
KDE
This is an acronym for K Desktop Enviornment; it is a open source graphical desktop enviornment for Unix workstations. It is easy to use with contemporary functions and outstanding graphical design.
Kenneth Iverson
Dr. Kenneth Iverson developed a programming language, J, which can be accessed from any ASCII keyboard and display. It was developed with the help of Roger Hui. Copies can be download at ftp://watserv1.uwaterloo.ca/languages/j/. Dr. Iverson created J as a means to introduce both mathematics and programming. He is the author of books that outline these methods.
Kerberos
The security system for MIT's Project Athena.
Kermit
A file transfer and terminal emulation program from Columbia University. Kermit can transfer text and binary files on many different computer platforms.
kernel
The essential part of a program or operating system, that performs the basic functions.
kerning
Reducing the spacing between certain pairs of letters in a proportional-pitch type to improve the appearance of the line of type. Proportional-pitch fonts often have automatic kerning of certain letter pairs; in a good type program, the operator can adjust the automatic kerning for style preference, or can kern individual pairs as needed. For example, A and V look better next to each other if they are moved closer together than, for example, A and B.
key
Each part of a keyboard that is pressed with a finger to input a character.
key cap
The top part of a keyboard key.
Key Caps
An interactive keyboard layout for Macintosh that shows for each typeface the characters available in uppercase, lowercase, and with option keys. The user picks a font from a pull-down menu, and the characters of that font show on the keyboard. Pressing the shift key will show the uppercase layout, and pressing the option key or option-shift will show additional characters. The equivalent utility for Windows is Character Map.
key entry
The entry of data by means of a keyboard.
key escrow
A policy of the United States government of allowing strong encryption technology to be exported pending the approval of the Commerce Department and under the condition that the company exporting the technology offer a third key to the government. Some United States companies have agreed to participate in the key escrow system. They include Ascend Communications, Cisco Systems Inc., 3Com Corporation, Hewlett-Packard Company, Nortel Networks, Novell Inc., and Sun Microsystems Inc., all members of the Alliance for Network Security.
key frame
In computer animation, a frame drawn directly by the animator which is at an important point in the action, such as the beginning or end of a movement. The frames in between key frames can be generated by the computer through a process called tweening.
key in
To enter data into the computer by means of the keyboard.
key recovery
An encryption arrangement in which a third party holds keys to unlock encrypted transmissions between two companies; this arrangement is supported by the U.S. government as a way to reserve access to encrypted transmissions when such access becomes necessary for criminal investigation or national security.
key repeat rate
The speed at which a character is repeated when its keyboard key is held down.
key-driven
Activated by means of a keyboard.
keyboard
A set of keys for computer input, which resembles a typewriter keyboard, but with a few extra keys for computer commands and usually a numeric keypad added. The original typewriter keys worked mechanically to make a metal hammer with a raised, inked type character on it strike a page. On a computer keyboard, hitting on a key sends an electrical signal to a microprocessor, which sends a scan code to the computer's basic input/output system. The BIOS translates the scan code into an ASCII code that stands for a character, which is read by the operating system or program so the character appears on the screen.
keyboard buffer
A memory area that stores keystrokes when a typist is too fast, to allow the program to catch up.
keyboard commands
Commands given by pressing keys on the keyboard; most keyboard commands require two keys pressed at once, and some require three or four keys pressed at once. For example, control-B, alt-G, command-shift-I.
keyboard key
Each part of a keyboard that is pressed with a finger to input a character. See also keyboard.
keyboard keys
The buttons on a keyboard that are pressed with a finger to input characters. See also keyboard, F keys, option key, QWERTY, Dvorak, ASCII.
keyboard overlay
A plastic template that can be fitted over the function keys to show how they are used within a particular program.
keyboard port
A port that connects a keyboard to the computer.
Keyboard Send Receive
(KSR). A keyboard send/receive terminal made by Teletype Corporation.
keyboard send-receive mode
(KSR mode). A mode in which a virtual terminal emulates a keyboard send/receive terminal.
keyboard send/receive
(KSR). A teletypewriter transmitter and receiver operated by means of a keyboard, with no monitor.
keyboard shortcut
A key combination that can be pressed to do a task, instead of using the mouse to select a pull-down menu option. Keyboard shortcuts can be found in the pull-down menus, where they appear next to the commands. A commonly-used keyboard shortcut in Windows or Macintosh is Control+S, which is a quick way to save a file.
keyboard-enhanced PDA
A personal digital assistant that has a keyboard; some of these can accept PC cards to expand memory or communications.
keying
Entering data by typing on a keyboard.
KeyNote Software
A company providing business directories for the software and multimedia industries.
keypad
A small keyboard; usually refers to the keys on a calculator or the
numerical keypad on a computer keyboard, which can be used with a calculator desktop utility.
keypal
An email pen pal. Some World Wide Web sites provide the service of helping people find keypals who share their interests.
keypunch
An old method of data entry in which a keyboard was used to activate a keypunch machine, which punched holes or notches in cards. The cards were fed into a computer to input data.
keypunch machine
An old-style data-entry machine which uses keyboard input to punch holes into cards by means of dies. The punched cards store data.
keystone
An effect which causes distortion of a projected image because the projector is not at a 90-degree angle to the screen. The distance to the top of the image on the screen is much greater than to the bottom. Usually the distorted image is wide at the top and narrow at the bottom; for example, a building may look like it is vanishing into the sky. This distortion especially happens on overhead projectors and front room projectors because they are placed so close to the screen. Keystoning may be corrected by adjusting the angle of the screen and by other techniques; see keystone correction.
keystone correction
A variety of methods that can be used to correct the keystoning effect often seen on overhead and front room projectors. For example, the angle of the screen can be adjusted. There are optical methods of keystone correction; some projectors apply a reverse keystone to the image, which cancels out the normal keystoning effect. Keystoning is less of a problem with mid-room projectors that can be located farther away from the screen. There are also digital methods of keystone correction, for example, in Photoshop 4.0.
keystoning
Distortion of a projected image because the projector is not at a 90-degree angle to the screen. The distance to the top of the image on the screen is much greater than to the bottom. Usually the distorted image is wide at the top and narrow at the bottom; for example, a building may look like it is vanishing into the sky. This distortion especially happens on overhead projectors and front room projectors because they are placed so close to the screen. Keystoning may be corrected by adjusting the angle of the screen and by other techniques; see keystone correction.
keystroke
Depression of a keyboard key; formulas (such as using Control keys to insert a frequently used phrase) that use fewer keystrokes make a typing job faster.
keyword
1. A word in a programming language that has a strictly defined meaning, such as goto, if, then, else. These words must be used only in the specific sense defined in the language. 2. A word used in a search, for example, to find World Wide Web documents relating to a particular subject.
Khornerstones
A benchmark program for testing a machine's CPU, I/O and floating point performance.
Khz
Kilohertz. Thousand cycles per second.
kick
To banish someone from an IRC channel, usually in response to bad behavior on the channel such as flooding. Only a channel op can kick a user.
Kid Pix
A children's drawing and painting program for Macintosh, from Broderbund Software.
Kill Cookie Batch File
A PC program that eats HTTP cookies, that is, removes them from the computer. See cookies.
kill file
A file for some Usenet reading programs which automatically discards certain articles according to criteria set up by the reader, such as subject or author. Items (such as people or subjects) added to the kill file will not be shown for reading.
killer app
An application that is an exciting technological breakthrough, or has important and useful features that make many people want to buy it.
killfile
A file for some Usenet reading programs which automatically discards certain articles according to criteria set up by the reader, such as subject or author. Items (such as people or subjects) added to the kill file will not be shown for reading.
kilo-
A prefix which means one thousand (10^3).
kilobaud
One thousand baud.
kilobit
(Kb, Kbit, K-bit, kbit). One thousand bits (103) or 1024 bits (210). A unit of measurement of the capacity of memory integrated circuits. Not to be confused with kilobyte.
kilobyte
(k, KB, Kb; also Kbyte or K-byte). One thousand bytes (103) or 1024 (210) bytes. A unit of measurement used for computer file sizes.
Kiloherz
(Khz). Thousand cycles per second.
kiosk
A small, stand-alone structure found on college campuses, in shopping malls, etc., which provides directories and other public information by means of a computer display and keyboard or touch screen.
KIPS
Thousands of instructions per second; a unit used to measure the speed at which a processor executes instructions. See also MIPS.
KIS
Knowbot Information Service. A directory retrieval service for Internet addresses, that uses intelligent agents to process requests. Also called netaddress.
KLOC
Stands for “thousands of lines of codes” — K refers to “thousands” and LOC refers to “Lines of Code.”
kludge
1. A crude or jerry-rigged, often short-term solution; a kludge can be hardware or software. 2. A program thought to be made in haste, or with little effort or forethought. Often a kludge will do the task, but lacks in efficiency or aesthetic quality.
klugey
Awkwardly designed; jerry-rigged; referring to hardware or software.
KMS
Knowledge Management System. A distributed system from Knowledge Systems, Inc. for managing knowledge in organizations.
KNI
Katmai New Instructions. The code name for MMX2 instructions.
Knight-Ridder Information Inc.
An online service in Mountain View, California, which provides access to over 400 databases.
Knowbot
A knowledge robot; a program that retrieves information on request.
Knowbot Information Service
(KIS). A directory retrieval service for Internet addresses, that uses intelligent agents to process requests. Also called netaddress.
knowledge acquisition
In AI (Artificial Intelligence), the acquisition of knowledge from humans which is entered into a computer and organized for use by an expert system.
knowledge base
A database of knowledge about a subject; used in artificial intelligence. The knowledge base for an expert system (a computer system that solves problems) comes partly from human experience and partly from the computer's experience in solving problems. The knowledge base must be expressed in a formal knowledge representation language for the computer to use it.
knowledge domain
A specific area of knowledge covered by a knowledge-based system.
knowledge engineer
An engineer who obtains knowledge from human experts and organizes it into a knowledge base for an expert system.
knowledge engineering
The design and development of knowledge-based systems.
Knowledge Management System
(KMS). A distributed system from Knowledge Systems, Inc. for managing knowledge in organizations.
knowledge representation
The branch of artificial intelligence that involves the design of systems for holding and representing knowledge.
knowledge source
In artificial intelligence, the source of data which is used to create a knowledge base.
knowledge system
A computer system that is programmed to imitate the problem-solving procedures human experts make. For example, in a medical system the user might enter data like the patient's symptoms, lab reports, etc., and derive from the computer a possible diagnosis. The success of a knowledge system depends on the quality of the data provided to the computer, and the rules programmed into the computer for making deductions from that data.
Knowledge Systems Laboratory
(KSL). An artificial intelligence research laboratory at Stanford University.
knowledge-based system
(KBS). A computer system that is programmed to imitate human problem-solving by means of artificial intelligence and reference to a database of knowledge on a particular subject.
Korn shell
(ksh) A command interpreter for UNIX.
ksh
Korn shell. A command interpreter for UNIX.
KSL
Knowledge Systems Laboratory. An artificial intelligence research laboratory at Stanford University.
KSR
Keyboard Send/Receive. A teletypewriter transmitter and receiver operated by means of a keyboard, with no monitor.
KSR mode
(Keyboard send-receive mode). A mode in which a virtual terminal emulates a keyboard send/receive terminal.
L1 cache
A level 1 (L1) cache is a memory cache that is built into the CPU chip. A fast transfer speed for a memory bus, the conduit between the CPU and main memory (DRAM), is 66MHz. The L1 cache is a small, fast memory area that works together with the L2 cache to provide the CPU much quicker access to important and frequently-used data than searching the main memory.
L2 cache
A level 2 cache (L2) is a collection of memory chips on the motherboard. The L2 cache is a static RAM secondary memory area which is slower than the L1 cache but faster than main memory. An L2 cache is typically 256KB or 512KB. Increasing a level 2 cache may speed up some applications and have no effect on others. The L1 cache and L2 cache are used together.
LaborNet
A network sponsored by the Institute for Global Communications for the purpose of improving worldwide communication on labor issues and gaining fair conditions for workers.
lambda-calculus
A system of mathematical logic Alonzo Church originated in the1930s, which concerns the application of functions to their arguments. Lambda-calculus and its variations have been important in the development of computer programming languages.
LAN
Local Area Network. A network that connects computers that are close to each other, usually in the same building, linked by a cable.
LAN emulation
A technology that uses asynchronous transfer mode to connect Ethernet and Token Ring networks together.
LAN Manager
Microsoft's network operating system for DOS, Windows, and OS/2.
LAN manager
The person who manages a local area network.
LAN station
A workstation in a local area network.
landing zone
An area on a hard disk where the read/write head lands when the disk stops rotating. No data is recorded in the landing zone.
landline
Traditional wired telephone service, rather than wireless service.
Landmark rating
A benchmark for PCs that measures CPU and coprocessor speed and video performance.
landscape
A way of positioning a page so it is wider than it is high, as in landscape painting. A computer printer usually gives the user a choice between landscape and portrait orientations.
language
A set of symbols that are used to communicate information, including rules for how the symbols are used.
language based editor
A computer program which is designed to help the user write and edit programs in a particular programming language. The editor has the rules of the language built into it, and can check for mistakes as programs are written or edited.
language processor
Software that performs language translation.
language-sensitive editor
A computer program which is designed to help the user write and edit programs in a particular programming language. The editor has the rules of the language built into it, and can check for mistakes as programs are written or edited.
A program from Traveling Software, Inc., that transfers data between laptops and desktop computers.
laptop
A portable personal computer that is small enough to fit in a person's lap. and weighs less than eight pounds. Laptops usually have a flat screen and LCD display, and are powered by a rechargeable battery. They can be connected to a larger monitor or other peripherals when back at the office.
laptop computer
A portable personal computer that is small enough to fit in a person's lap. and weighs less than eight pounds. Laptop computers usually have a flat screen and LCD display, and are powered by a rechargeable battery. They can be connected to a larger monitor or other peripherals when back at the office.
large-scale integration
(LSI). The use of integrated circuits with more than 100 logic gates. Fourth-generation computers have large-scale integration.
laser
light amplification through stimulated emissions of radiation
A device that uses the oscillation of atoms or molecules between energy levels to generate a narrow, finely focused beam of light. The light has a single wavelength or narrow spectrum of wavelengths and is matched in phase and frequency. Lasers are used in fiber-optics, laser printers, CD-ROM players, and scanners.
laser beam
The beam of light produced by a laser, which can be precisely focused and can travel great distances without much loss of power.
laser beam printer
A high-speed, non-impact printer that uses a laser beam to form images on a page. Laser beam printers produce high-resolution, high-quality printouts.
laser disc
(LD). An optical disc which stores information that can be read by a laser beam. Laser discs can be used to store data, but are usually used for video and audio together. Laser discs come in 8″ and 12″ diameters. Information can be stored in constant linear velocity or constant angular velocity format. The 8″ laser discs can hold up to 20 minutes of video per side; the 12″ size holds up to 60 minutes per side.
laser printer
A high-speed, non-impact printer that uses a laser beam to form images on a page. Laser printers work like photocopiers to produce high-resolution, high-quality printouts.
LaserDisc
A trademark of Pioneer Electronics USA, for its laser disc products.
LaserJet
A series of laser printers from HP, beginning with the first desktop laser printer in 1984, which revolutionized desktop publishing. Color printers are now available.
LaserWriter
A series of desktop laser printers from Apple.
Last In First Out
(LIFO). A method of storage in which the data stored last will be retrieved first.
Last In Last Out
(LILO). A method of storage in which the data stored last will be retrieved last.
LATA
Local Access and Transport Area. A geographical area designated by the telephone company, usually having the same area code.
latency
1. The time lag between the beginning of a request for data and the moment it begins to be received. 2. When reading data from memory, the number of processor cycles per bit delivered. 3. The time necessary for a packet of data to travel across a network. 4. The time it takes for the light emitted from a phosphor on a display screen to dim.
LaTeX
Lamport TeX. Document preparation software; a variation of TeX.
launch
To load a program and start it.
LAWN
Local Area Wireless Network. A technology from O'Neill Communications, Inc., for wireless networking using a radio transmitter/receiver.
Lawrence Livermore National Laboratory
(LLNL). A science and engineering research laboratory operated by the University of California under contract with the U.S. Department of Energy.
layout
The design and formatting of a page for publication. Layout used to be done by manually laying the elements of a page in place and fixing them to the page with wax. Now most layout is done onscreen, using a computer program, and there may never be a hard copy of the page.
layout settings
Settings used to format a page for publication, which can include such specifications as margins, indents, column widths, word wrap, and tabs.
LB
Low Battery. A modem status signal indicated by a light on the modem.
LCC
1. Leaded Chip Carrier. A square chip package with pin connectors on each side. 2. Leadless Chip Carrier. A square chip package with flat contacts, instead of pin connectors, on each side; also abbreviated LLCC. The leadless chip carrier is easier for the user to install. The user puts it into a specially designed socket and closes a clamp to establish its connections.
LCD
Liquid Crystal Display. A type of display used on digital watches, calculators, and laptop computers. LCDs are lighter and consume much less power than other computer displays. Liquid crystals are rod-shaped molecules which spiral when they are exposed to an electrical charge. Polarized light passing through the layer of liquid crystal cells is twisted along the spiral path of the molecules. The light then passes through a series of filters which block light vibrating at certain angles and allow light vibrating at other angles to pass through; thus the color of each pixel can be controlled.
LD
Laser Disc. An optical disc which stores information that can be read by a laser beam. Laser discs can be used to store data, but are usually used for video and audio together. Laser discs come in 8″ and 12″ diameters. Information can be stored in constant linear velocity or constant angular velocity format. The 8″ laser discs can hold up to 20 minutes of video per side; the 12″ size holds up to 60 minutes per side.
LDAP
Lightweight Directory Access Protocol. An online directory service protocol defined by the Internet Engineering Task Force (IETF) which is a simplification of Directory Access Protocol (DAP). An LDAP directory entry is a collection of attributes with a unique identifier, called a distinguished name (DN). The directory system is in a hierarchical structure. See also X.500, DAP, DN.
LE
Less than or equal to: <= .
lead acid battery
A kind of rechargeable battery that has been used in some portable computers. It uses lead plates with an acid electrolyte. The lead acid battery provides less charge per pound than the nickel cadmium or nickel hydride batteries.
leaded chip carrier
(LCC). A square chip package with pin connectors on each side.
leader
1. A line of dots, dashes, or sometimes other symbols used to lead the reader's eye across a page, such as in a menu or table of contents. 2. A section of blank tape used to thread a tape up to the point where it begins recording or playing.
leader tab
A tab that has a leader (a row of dots, dashes, or other characters) preceding the tab entry.
leading
The vertical spacing between lines of type or other design elements, usually measured from baseline to baseline. In early linotype machines, the space between lines was made with bars of lead. Leading is measured in points; standard leading is 120% of the height of the text. So a 10-point typeface would normally have 12-point leading; however, leading can be adjusted to any desired setting. Simple word processors allow only for single-spacing, double-spacing, and space-and-a-half; more sophisticated type programs allow finer leading adjustments.
leading zeros
Zeros on the left side of a number, used to fill in a field; they have no effect on the value of the data. For example, the zeros in 000054.
leadless chip carrier
(LCC or LLCC). A square chip package with flat contacts, instead of pin connectors, on each side. The leadless chip carrier is easier for the user to install than the leaded chip carrier. The user puts it into a specially designed socket and closes a clamp to establish its connections.
leaf
1. In a hierarchical file system, a file on the lowest level. The hierarchical file system is described as a tree with a descending system of directories similar to roots, branches, and leaves. 2. The last node of a tree in database management. 3. A sheet of paper in a document; each side of the leaf is a page.
League for Programming Freedom
(LPF). A nonprofit organization dedicated to “bringing back the freedom of programmers to write programs,” in the face of the recent trend toward complicated copyright and patent lawsuits. Address: 1 Kendall Square #143, P.O.Box 9171, Cambridge, Massachusetts 02139 U.S.A. (http://www.lpf.org/).
leapfrog test
A self-replicating diagnostic routine for checking the capacity of storage media such as disks and tape.
learnware
Educational software.
leased line
A dedicated line that is leased exclusively to connect two points, 24 hours a day, 7 days a week. A leased line gives the highest-speed connection.
leased line modem
A high-speed modem used on a private leased line. It may also be used for dial-up connections, for which it must use a lower speed.
least significant bit
(LSB). The bit of a binary number which is farthest to the right, indicating the number of ones; also designated as bit zero.
least significant digit
The significant digit which is farthest to the right in a number.
LED
Light-Emitting Diode. A type of semiconductor diode that emits visible or infrared light when current passes through it. Visible LEDs are used as indicator lights; for example, the light that shows a computer or printer is turned on. Infrared LEDs are used in remote-control devices.
LED printer
A printer which is similar to a laser printer, but uses light-emitting diodes in place of the laser.
left arrow
A keyboard key which has a picture on it of an arrow pointing left; it moves the cursor to the left on the page.
left brace
ASCII character 123: { .
left bracket
ASCII character 91: [ .
left click
Clicking the left side button on the mouse.
left justified
Aligned on the left margin; same as flush left.
left paren
ASCII character 40: ( . Also called left parenthesis.
left parenthesis
ASCII character 40: ( . Also called left paren.
left tab
A tab that has left alignment. The text is aligned on the left and extends to the right of the tab stop.
legacy application
An application that has been in use for a long time, usually on a mainframe or minicomputer.
legacy system
An information system that has been in use for a long time, usually on a mainframe or minicomputer.
legend
Explanatory text on a chart, map, or illustration.
Lempel-Ziv compression
A data compression algorithm developed by Jacob Ziv and Abraham Lempel.
Lempel-Ziv Welch compression
LZW compression. A compression algorithm designed by Terry Welch based on the LZ77 and LZ78 compression techniques developed by Jacob Ziv and Abraham Lempel. LZW compression is used for both archiving and transmitting files.
less than
ASCII character 60: < .
letter quality
(LQ). Printing quality as good as, or better than, the best typewriters. Laser printers produce letter quality printing, and some inkjet and dot-matrix printers do also.
letter quality printer
A printer that can print letter quality; in other words, quality as good as that of a good electric typewriter.
letter row
On a keyboard, a row of keys that has mostly letters.
letterbomb
An electronic mail message that contains some code that is intended to do harm to the recipient's computer.
level 1 cache
A level 1 (L1) cache is a memory cache that is built into the CPU chip. A fast transfer speed for a memory bus, the conduit between the CPU and main memory (DRAM), is 66MHz. The L1 cache is a small, fast memory area that works together with the L2 cache to provide the CPU much quicker access to important and frequently-used data than searching the main memory.
level 2 cache
A level 2 cache (L2) is a collection of memory chips on the motherboard. The L2 cache is a static RAM secondary memory area which is slower than the L1 cache but faster than main memory. An L2 cache is typically 256KB or 512KB. Increasing a level 2 cache may speed up some applications and have no effect on others. The L1 cache and L2 cache are used together.
lexeme
The minimal lexical unit of a language, whether a natural language or a computer language.
lexical analysis
The first stage of processing a computer language, in which a lexical analyzer reads the input and groups characters into lexemes (elemental units of language), which are then sent on to the parser.
lexical analyzer
A program that analyzes computer language input and groups the stream of characters into wordlike units called lexemes. The output of the lexical analyzer is next processed by the parser.
lexicographic sort
A sorting of items in alphabetical order.
Lexmark
Lexmark International, Inc. A company that manufactures dot matrix printers, keyboards, and related products.
LF
1. Line Feed. Feeding the paper through the printer just far enough to print the next line. Also, a button or computer instruction that activates a line feed. 2. Low Frequency. Electromagnetic frequencies in the range of 30 to 300 kiloherz.
LHARC
A shareware/freeware compression and archiving program developed by Haruyasu Yoshizaki. Compressed files have the extension .lha.
li-ion
Lithium-ion, a long-lasting type of rechargeable battery used in portable computers. A lithium ion battery can go four or five hours without recharging.
license agreement
A legal statement which indicates the terms under which a user may make use of a software product. The license to use does not transfer ownership. In many cases the license is worded so that installation or use of the product indicates agreement to the terms stated.
LIFO
Last In First Out. A method of storage in which the data stored last will be retrieved first.
ligature
Two or more type characters that touch, used especially in book typesetting. Some common ligatures are ff, fl, ffi, tt, ae.
light pen
A light-sensitive pen pressed against a touch screen for drawing or communicating with the computer.
light waves
Light has wavelengths between 10 nanometers and one millimeter, which spans from the infrared to the visible spectrum to the ultraviolet range.
light-emitting diode
(LED). A type of semiconductor diode that emits visible or infrared light when current passes through it. Visible LEDs are used as indicator lights; for example, the light that shows a computer or printer is turned on. Infrared LEDs are used in remote-control devices.
Lightweight Directory Access Protocol
(LDAP). An online directory service protocol defined by the Internet Engineering Task Force (IETF) which is a simplification of Directory Access Protocol (DAP). An LDAP directory entry is a collection of attributes with a unique identifier, called a distinguished name (DN). The directory system is in a hierarchical structure. See also X.500, DAP, DN.
lightweight protocol
A simplified communications protocol.
LILO
Last In Last Out. A method of storage in which the data stored last will be retrieved last.
limited distance modem
A modem that can send communications for short distances, usually about a mile.
line dot matrix printer
A printer that prints one line at a time and uses the dot matrix method.
line drawing
A drawing made by solid lines outlining a figure. Line drawings are the simplest images in computer graphics, as they require only black and white (or one color and white). Images which have subtle shades are called grayscale images.
line driver
On a private communications line, a device that increases the possible transmission distance between stations; each end of the line must have a line driver.
line feed
(LF). Feeding the paper through the printer just far enough to print the next line. Also, a button or computer instruction that activates a line feed.
line graphics
A way of representing pictures by designating coordinates and drawing lines or geometric shapes in relation to them. Line graphics are different from bitmapped graphics, in which an image is stored as a collection of pixels. In line graphics, the image is saved as a file containing instructions for drawing it.
line noise
Extraneous characters that appear in a computer transmission because of electrical noise in the communications link, which may be caused by a poor connection, electrical storms, or other problems.
line print terminal
(LPT). On a personal computer, the usual designation for a parallel port connection to a printer or other device such as a scanner or camera. LPT connections are numbered LPT1, LPT2, LPT3, etc.; most computers have at least one. More parallel ports can be added by installing parallel port adapter cards.
line printer
A printer that prints one line at a time. Dot matrix printers are line printers.
line probing
An ability of some modems to adjust their transmission rate according to the quality and capacity of the telephone line.
line spacing
A way of specifying vertical space between lines on a document by single spacing, double spacing, or one-and-a-half line spacing. Line spacing is not as fine-tuned a measurement as leading, but is good for letters, manuscripts, and many word processing uses.
line squeeze
A function in a mail merge operation that eliminates lines which have no data so there will not be a blank space on the label.
linear video
A video on tape that is viewed or edited in a linear sequence. CD-ROMs and LaserDiscs can display nonlinear video, in which the user can jump from frame to frame or clip to clip in any order.
linear video editing
The original process of editing analog videotape by inserting frames. Nonlinear video editing using digital processes is easier and becoming more common.
lines per inch
(lpi). A measurement of the resolution of a halftone screen, or of the number of lines a printer prints on a page in each vertical inch.
lines per minute
(lpm). A measurement of printer or scanner speed.
link
1. A connector; anything that connects two or more things. 2. A pointer in an HTML document that leads to another World Wide Web site, or to another place within the same document; also called a hyperlink. Linked text is usually underlined or shown in a different color from the surrounding text. Sometimes graphics are links or contain links. A link is activated by clicking on it. 3 A pointer embedded in a database record that refers to data or the location of data in another record. 4. A line or channel for transmitting data. 5. A call from a program to another program or subroutine. 6. To connect with a link.
link dead
A condition in which a network connection has failed.
linked list
A list in which each data element has information for locating the next. The data elements may be in noncontiguous storage locations.
linked list search
A search that uses a linked list.
linotype
An old keyboard-operated typesetting machine that produced each line of type as a solid metal slug. A bar of lead between lines of type provided the spacing, called leading.
Linotype
Trademark for the typesetting machine invented by Ottmar Mergenthaler in 1886, which quickly brought about a revolution in the printing industry.
LINPACK
A package of linear algebra software routines, and a benchmark developed from them.
Linux
An Open Source implementation of UNIX created by Linus Torvalds, which runs on many different hardware platforms including Intel, Sparc¨, PowerPC, and Alpha Processors. Hundreds of application programs have been written for Linux, some of these by the GNU project. Linux and Linux tools can be downloaded via the Internet or BBS for free, or purchased as part of a distribution on a CD-ROM.
LIPS
Logical Inferences Per Second. In artificial intelligence, the speed at which an application can process instructions. The human brain works at about 2 LIPS.
Liquid Crystal Display
(LCD). A type of display used on digital watches, calculators, and laptop computers. LCDs are lighter and consume much less power than other computer displays. Liquid crystals are rod-shaped molecules which spiral when they are exposed to an electrical charge. Polarized light passing through the layer of liquid crystal cells is twisted along the spiral path of the molecules. The light then passes through a series of filters which block light vibrating at certain angles and allow light vibrating at other angles to pass through; thus the color of each pixel can be controlled.
List Processor or List Processing. A programming language developed at MIT in the 1950s by John McCarthy. Lisp, based on lambda calculus, is widely used in artificial intelligence programs because it handles complex data structures more easily than other programming languages. Lisp is characterized by list processing, recursion, and character string manipulation. Lisp statements are linked lists; data objects may be lists or atoms.
list
1. An ordered set of data items. 2. To display a program line by line. 3. A command that causes the computer to display a list of items.
list administrator
The person who maintains a mailing list (an online discussion carried on by mailing copies of all correspondence to all the participants).
list box
A scrollable area within a dialog box where the user can choose from a list of items.
list processing
Processing data in the form of lists. List processing languages provide special commands to do this.
list processing language
A programming language which is used to process lists of data. Examples are LISP and Prolog.
Listproc
A UNIX automated mailing list server developed and owned by BITNET.
listserv
An automated email discussion list.
Listserv
An automated mailing list server first used on the BITNET/EARN network. Through Listserv, users can join or remove themselves from mailing lists, and make use of other services, by sending email messages. Listserv was originally designed to run on the IBM VM operating system.
lit fiber
Fiber-optic cable which is actively carrying a signal. When the cable is not carrying a signal, it is called dark fiber.
literal
In computer programming, a constant, or an instruction that remains unchanged; a literal is a value that is defined at compile time and cannot be modified by the programmer during run time.
literate programming
A programming method in which explanatory text accompanies the instructions in the computer programming language. The computer instructions may be marked to separate them from the text instructions, whereas in most programs it is the text comments that are marked.
lithium ion battery
The longest-lasting type of rechargeable battery used in portable computers. A lithium ion battery can go four or five hours without recharging.
lithium polymer technology
A technology which may provide more and longer-lasting power than lithium ion batteries for notebook computers.
little-endian
A binary data format in which the least significant bit would be on the left.
live chat
Online typed conversation in real time.
liveware
Living beings; people.
LLCC
Leadless Chip Carrier. A square chip package with flat contacts, instead of pin connectors, on each side. The leadless chip carrier is easier for the user to install than the leaded chip carrier. The user puts it into a specially designed socket and closes a clamp to establish its connections.
LMB
Left Mouse Button.
LMC
Left Mouse Click.
LMK
Let Me Know (chat).
ln
Natural (base e) logarithm.
load
1. To copy a program into memory so it can be run. 2. To put a disk or tape into a drive so it can be used. 3. To put data onto a disk so it can be used. 4. To make a font available for use on the computer.
loader
A computer program that loads another program into memory. All operating systems include loaders. When the user opens a program, the loader loads it and then transfers control to the program.
local
In communications, referring to equipment that is accessed directly without a telecommunications line.
Local Access and Transport Area
(LATA). A geographical area designated by the telephone company, usually having the same area code.
local area network
(LAN). A network that connects computers that are close to each other, usually in the same building, linked by a cable.
Local Area Wireless Network
(LAWN). A technology from O'Neill Communications, Inc., for wireless networking using a radio transmitter/receiver.
local bus
An extra bus in addition to the main bus in a computer, which provides a fast data path connecting the CPU with memory and peripherals. The local bus is designed to run at the speed of the CPU. The most common local busses are VLB (VESA Local Bus) and PCI (Peripheral Component Interconnect).
local bypass
A local telephone connection that does not have to be made through a telephone company.
local drive
A disk or tape drive that is connected to one's local computer, rather than on a network.
local memory
1. In a system that has more than one processor, the memory used by a specific processor that is not available to other processors. 2. Memory designated for use by a particular program or function.
local resource
A peripheral device that is directly connected to a local computer.
local storage
Disk storage used by one particular processor.
local system
The computer system the user is working on. The remote system is any other system in the network with which the local computer can communicate.
localization
Altering an operating system so the user interface is appropriate for the region or country in which it is used. Oftentimes this will necessitate the changing of sorting tables, terminology, times, measures, language and its colloquialisms. Contrast with internationalization.
A condition in which a computer cannot respond to user commands.
log
1. A record of a computer's or application's activity, used for system information, backup, and recovery. 2. Abbreviation for logarithm.
log file
A file that keeps track of a computer’s or application’s activity, for example, network connections.
log in
1. The act of accessing a computer system, usually by typing a username and password on a terminal. Contrast with log-in.
log off
To exit a network or remote system.
log on
To access a network or remote system. Logging on often requires a password.
log out
1. To disconnect from a network by typing logout, exit, quit, or a similar word. 2. To disconnect from a computer system.
log-in
The account name used to access a computer system. Contrast with log in
logarithm
The exponent showing the power to which a fixed number, the base, must be raised to produce a certain number. For example, 3 to the power of 2 = 9; the logarithm of 9, with 3 as the base, is 2.
logic board
The main circuit board inside a computer, which contains the central processing unit, the bus, memory sockets, expansion slots, and other components; also called the motherboard.
logic bomb
Code that is hidden in a program or system which will cause something to happen when the user performs a certain action or when certain conditions are met. A logic bomb, which can be downloaded along with a corrupted shareware or freeware program, may destroy data, violate system security, or erase the hard drive. It is not the same as a virus because the logic bomb executes once, or at periodic intervals, whereas the action of a virus is ongoing.
logic error
An error caused by a mistake in programming instructions. A logic error causes a program to operate wrongly or produce incorrect data, but not to stop working.
logical inferences per second
(LIPS). In artificial intelligence, the speed at which an application can process instructions. The human brain works at about 2 LIPS.
logical operator
One of the Boolean operators AND, OR and NOT.
logoff
The act of disconnecting from a network or remote system.
logon
The process of connecting to a network or remote system.
logout
1. The act of disconnecting from a network by typing logout, exit, quit, or a similar word. 2. The act of disconnecting from a computer system.
long card
A full-sized PC expansion card.
lossless compression
Compression methods in which no data is lost. With lossless compression, a large file can be compressed to take up less space, and then decompressed without any loss of information. In the case of graphics or video files, the quality of the original image will be preserved. An example of a lossless compression algorithm is gzip.
lossy compression
A compression technique in which a file can be highly compacted, but some data is lost. Large files such as graphics, video, or audio files can be stored in a smaller amount of space than with lossless compression, but some loss of quality will result when the file is decompressed. Examples of lossy compression algorithms are JPEG and MPEG.
Lotus 1-2-3
A widely-used spreadsheet program for DOS, Windows, Macintosh, Sun, VAX, OS/2, and UNIX, from Lotus Development Corporation.
A software company that produced Lotus 1-2-3, Symphony, and Lotus Notes.
low frequency
(LF). Electromagnetic frequencies in the range of 30 to 300 kiloherz.
low resolution
A low number of dots or lines per inch. Low-resolution images use less memory but result in a lower print or display quality.
low-level language
A computer programming language that is close to machine language. Machine language is at the lowest level, because it is the actual binary code of 1s and 0s that the computer understands. Assembly languages are low-
level languages which are translated into machine code by an assembler. Each assembly language instruction corresponds to one machine language instruction, but assembly language is easier notation for the programmer to use than machine code.
low-radiation monitor
A computer monitor that is designed to minimize the radiation it emits. VLF (very low frequency) and ELF (extremely low frequency) radiation from computer screens are a health concern, but their effects are not known.
lower case
The non-capitalized letters on the keyboard.
lower letter row
The lower letter row (row of letter keys) on a keyboard.
lowercase
Not capitalized; referring to letters on the keyboard.
LPF
League for Programming Freedom. A nonprofit organization dedicated to “bringing back the freedom of programmers to write programs,” in the face of the recent trend toward complicated copyright and patent lawsuits. Address: 1 Kendall Square #143, P.O.Box 9171, Cambridge, Massachusetts 02139 U.S.A. (http://www.lpf.org/).
lpi
Lines Per Inch. A measurement of the resolution of a halftone screen, or of the number of lines a printer prints on a page in each vertical inch.
lpm
Lines Per Minute. A measurement of printer or scanner speed.
lpr
A UNIX command to print a file.
LPT
Line Print Terminal. On a personal computer, the usual designation for a parallel port connection to a printer or other device such as a scanner or camera. LPT connections are numbered LPT1, LPT2, LPT3, etc.; most computers have at least one. More parallel ports can be added by installing parallel port adapter cards.
LQ
Letter Quality. Printing quality as good as, or better than, the best typewriters. Laser printers produce letter quality printing, and some inkjet and dot-matrix printers do also.
ls
A UNIX command to list the contents of a directory.
LSB
Least Significant Bit. The bit of a binary number which is farthest to the right, indicating the number of ones; also designated as bit zero.
LSI
Large-Scale Integration. The use of integrated circuits with more than 100 logic gates. Fourth-generation computers have large-scale integration.
LT
Less than: < .
LUG
Linux User Group.
Lukasiewicz notation
The same as Polish notation, which is a way of expressing a sequence of calculations without using parentheses to show which operation must be performed first. For example, the expression 2(4+5), which instructs the reader to add 4 + 5 and multiply by 2, would be written * 2 + 4 5 in Polish notation. To make the calculation, read from right to left until you find an operation, then perform the operation on the numbers immediately to the right of it, and continue to the next operation. So * 2 + 4 5 becomes * 2 9 and then 18. Reverse Polish notation is worked from left to right. Polish notation was invented by Jan Lukasiewicz, a Polish logician.
Lukasiewicz, Jan
A Polish logician (1878-1956), the inventor of Polish notation.
lumen
A unit of measurement of the rate at which light is emitted from a source. The International System unit of luminous flux, equal to the light emitted in a unit solid angle by a uniform point source of one candela.
luminance
Brightness; the amount of light, in lumens, that is emitted by a pixel or an area of the computer screen.
lurk
To visit an online discussion and read other people's postings without contributing any comments of one’s own. Lurking is a good way for a beginner to get familiar with a newsgroup or forum.
lurker
A visitor to an online discussion who reads other people's postings but does not contribute. Lurking is a good way for a beginner to get familiar with a newsgroup or forum.
lurking
Visiting an online discussion and reading other people's comments without contributing. Lurking is a good way for a beginner to get familiar with a newsgroup or forum.
LVD
low voltage differential.
Lview Pro
A Windows utility for viewing GIF, TIFF, and JPEG files.
Lycos
An Internet search engine (http://www.lycos.com/) created at Carnegie Mellon University.
Lynx
A freely distributed text-based World Wide Webbrowser originally developed at the University of Kansas. Lynx cannot display images, but is widely used in non-graphical systems in universities, libraries, and freenets, and by others who want to bring the World Wide Web to as wide an audience as possible. HTML pages with graphics will often provide alternative information for text-based browsers. The most recent, and probably final, release of Lynx distributed by the University of Kansas is 2.4.2. Lynx 2.7 is maintained by Foteos Macrides at the Worcester Foundation for Biological Research. Lynx runs on UNIX and VMS systems, and can run on DOS, Windows, and Macintosh with VT100 terminal emulation. The name is a pun on “links”.
LZ77
A compression technique developed by Jacob Ziv and Abraham Lempel, later used with LZ78 to create the LZW compression algorithm. LZ77 works by scanning through a fixed length block of data and eliminating repeating data by substituting a pointer back to the original data.
LZ78
A compression technique developed by Jacob Ziv and Abraham Lempel, later used with LZ77 to create the LZW compression algorithm. LZ78 works by scanning through a block of data and creating a dictionary of repeating phrases; instead of repeating a section of data, a pointer that indicates the original data is substituted.
lzexe
A DOS executable file compression program. It decompresses when it is executed.
LZW compression
Lempel-Ziv Welch compression. A compression algorithm designed by Terry Welch based on the LZ77 and LZ78 compression techniques developed by Jacob Ziv and Abraham Lempel. LZW compression is used for both archiving and transmitting files.
M
One million.
Mac
A brand name and registered trademark for a line of computers from Apple Inc.
MAC address
Media Access Control address. The physical address of a device connected to a network, expressed as a 48-bithexadecimal number.
Medium Access Control protocol. In a local area network, the protocol that determines which device has access to the transmission medium at a given time.
MAC sublayer
Medium Access Control sublayer. The lower sublayer of the data link layer, which uses the network's physical layer to provide services to the logical link control (LLC). The functions of the MAC sublayer vary according to the topology of the network.
MacApp
A tool for developing application programs on the Macintosh, using object-oriented Pascal.
MacBench
A benchmark from Ziff-Davis that measures the processor, floating point, disk, graphics, video, and CD-ROM performance of a MacOS, giving an idea of how well a particular system will run common Macintosh applications.
MacBinary
Macintosh files, unlike files from other computer platforms which hold data only, have a resource fork and a data fork. If Mac files are put on a non-Mac machine, the resource fork will be stripped off, rendering some files unusable. MacBinary encoding prevents loss of the resource fork when posting the file to a non-Mac platform, by attaching the resource and data forks together in a single data file. MacBinary files must be transferred using an 8-bit, binary mode. They often have .bin as a filename extension.
MacBooz
A Macintosh decompression program that can expand .zoo files.
MacCompress
The Mac version of the Compress program for DOS and UNIX. It creates files with the .Z suffix.
MacDraw
A drawing program for the Macintosh.
MacGzip
A version of gzip for Macintosh, made by SPDsoft. It compresses Mac files into gzip files; the Mac resource fork is lost unless a MacBinary translator is used first. The gunzip function decompresses .gz, .Z, .z, and .tgz files.
machinable
Readable by a computer; softcopy is machinable.
machine
A device which performs a task and is operated mechanically, electrically, or electronically. In computer terminology, “machine” refers to the computer itself.
machine address
An address that is permanently assigned to a specific storage location in a computer, by the maker of the machine.
machine code
Machine language. The language which is actually read and understood by the computer.
machine cycle
The cycle of four steps a computer's central processing unit must complete each time a machine language instruction is given: fetching the instruction from the main memory, decoding it, executing the instruction, and storing the result. “Machine cycle” also means the length of time one machine cycle takes.
machine language
(Same as machine code.) The language which is actually read and understood by the computer. Machine language consists of instructions, written in binary code, that a computer can execute directly. Each machine language statement corresponds to one machine action. An operation that requires one machine-language instruction in one computer may require several instructions in another computer.
Humans do not usually write programs in machine language, but use a programming language which the computer translates into machine language. Assembly language is the next level of programming. Each assembly-language statement corresponds to one machine-language statement, but assembly language statements are written in a symbolic code that is easier for humans to read.
machine learning
The ability of a machine to recognize patterns that have occurred repeatedly and improve its performance based on past experience.
machine-dependent program
A program that works only on one type of computer.
machine-independent program
A program that can work on many different types of computers.
machine-readable data
Data in any form that a computer can read as input. Magnetic disks, optical disks, and magnetic tapes contain machine-readable data.
Macintosh
A family of 32-bit personal computers introduced by Apple in 1984; the first widely used computers with a graphical user interface, a mouse, and windows. Rather than typing in commands, users open software and copy or delete files by clicking on icons on the screen that look like file folders, a trash can, and other things one would find in a real office. Macs quickly became popular because of their user-friendly interface. In 1994, PowerMacs, which use a PowerPC CPU, became available. The Macintosh Operating System is now called MacOS.
Macintosh clone
A Power Macintosh not made by Apple Computer.
Macintosh extensions
Software functions which can be added to the Macintosh by putting them in the Extensions folder within the System folder, including drivers and INITs. Some examples are Print Monitor, Thread Manager, Macintosh Drag and Drop, QuickTime, Audio CD Access, Apple Modem Tool.
Macintosh file
A Macintosh file has two forks: a data fork, which contains data (the same as files on other operating systems); and a resource fork, which has other attributes such as menus, icons, dialog boxes, formatting, and other codes. In some methods of converting files for transfer (such as uuencoding), the resource fork of a Macintosh file is stripped off and only the data fork is sent. BinHex and MacBinary encoding preserve the resource fork.
Macintosh user interface
The graphical user interface used by Macintosh personal computers, which is modeled after an actual desktop and has little pictures (called icons) of file folders, a trash can for deleting files, etc. Pull-down menus and draggin objects originated with the Mac. For people who are not computer experts, the Macintosh user interface makes everything much easier to learn. Parts of this interface were developed by Xerox PARC, but never released. Elements of the Macintosh user interface are now used on many other programs and operating systems, including Commodore, Amiga, Motif, OS/2 Presentation Manager, Digital Research's GEM, Hewlett-Packard's New Wave, the X Window System, RISC OS, and Microsoft Windows. Pull-down menus are used in graphical Internet browsers and on WWW pages.
Macjordomo
A Mac freeware listserver.
MacPaint
A paint program for the Macintosh computer.
macro
One instruction that represents a sequence of simpler instructions.
macro-
A prefix meaning large.
macro-assembler
A program that translates assembly language instructions into machine code and which the programmer can use to define macro instructions.
Macromedia
A software company in San Francisco, CA, which produces multimedia and digital arts tools for Microsoft Windows and Macintosh. Macromedia products include: Macromedia Director, Macromedia FreeHand, SoundEdit 16, and Fontographer.
macrotape
A larger-sized reel of magnetic tape, rather than a microtape.
MacTar
A compression program for Macintosh that creates and decompresses .tar files.
MacTCP
A Macintosh control panel which connects the computer with access to TCP/IP services.
MacTicker
A stock market program for Macintosh.
MacZoo
A Macintosh program that can decompress .zoo files.
MAD
Michigan Algorithm Decoder. One of the first extensible languages, developed at the University of Michigan.
MADAM
Manchester Automatic Digital Machine. One of the first chess-playing machines, developed by Alan M. Turing (1912-1954) in 1950. It was not very smart.
Magellan
An Internet search engine.
Magic Cookie
Magic Cookie is a file created by Microsoft Explorer and Netscape Navigator, kept in the preferences folder. The file stores data about what websites and pages within the site the user visits. This information can be used by the servers for marketing analysis, to generate mailing lists, or other uses. See cookie.
magic wand
A tool in some photo editing programs that allows the user to select an area of the image to copy, move, color, rotate, enlarge, or transform in other ways. Clicking on a pixel activates the whole area of the same color that is continuous with that pixel.
magnetic bubble memory
A kind of storage used in some lightweight portable computers. A magnetic bubble is a tiny movable magnetized cylindrical volume in a thin magnetic material that in combination with other similar volumes can be used to represent a bit of information.
magnetic disk
A hard disk or floppy disk, the primary means of data storage for a computer. Data on disks is magnetically recorded and can also be erased and re-recorded. The data is stored in concentric rings called tracks, which are further divided into numbered sectors. The disk rotates as a mechanical arm moves a read/write head back and forth. The head writes data by aligning magnetic particles on the disk's surface, and reads data by detecting the polarities of particles that have already been aligned.
magnetic field
The area around a magnetic body or a current-carrying body in which its magnetic forces can be detected. Magnetic forces have the property of attracting iron.
Magnetic Ink Character Recognition
(MICR) A character recognition system used on bank checks; special ink and characters are used, which can be magnetised for automatic reading.
magnetic tape
A data storage medium used for backup. The tape is made of a thin plastic strip with a magnetisable oxide coating on one side. To read or write, the tape drive winds the tape from one reel to another, causing it to move past a read/write head. Tapes are available in reels and cartridges of various sizes. The data is written in blocks with interblock gaps between them. To find a specific block of data on the tape the computer must read everything in front of it.
magnetic tape drive
A drive that reads and writes magnetic tape.
magneto-optical disk
A plastic or glass disk coated with a chemical (often TbFeCo) with special properties which make it rewritable. A combination of magnetic and optical methods are used to write data to the disk. A high-intensity laser heats the material up to its Curie point, the temperature at which molecules can be realigned by a magnetic field. A magnet is used to make changes in polarity which remain after cooling. The disk is read by directing a low-intensity laser at the disk and interpreting variations in its reflected light, which result from differences in polarity of the stored magnetic field.
mail bomb
Massive amounts of electronic mail sent to a single person, with malicious intent to overload the recipient’s system. Mail bombing can cause problems not only for the targeted recipient, but also for other users of the networks involved.
mail bridge
A gateway that forwards electronic mail messages between networks.
mail exploder
Part of an electronic mail system used by mailing lists. User send messages to a central address; the mail exploder delivers the messages to all individual mailboxes in its list.
mail filter
A program which can sort and process incoming email for the recipient, based on the mail headers. For example, all mail pertaining to a certain subject (as indicated by its header) could be put into a high-priority file.
mail gateway
A machine that makes a connection between two or more electronic mail systems in order to transfer messages, and translate between dissimilar systems.
mail hub
A computer which stores and/or forwards electronic mail.
mail log
An electronic mail program's record of all mail that has been sent and received.
mail merge
A way of using a computer to print customized form letters. The letter will be in one file, and a name and address list in another. Name and address information for each letter to be printed will be inserted at designated merge points. Other custom data can also be inserted at chosen points as specified by the user.
mail server
A program that sends files in response to requests sent by email.
mail transfer agent
(MTA) The program that delivers email messages. The mail transfer agent receives a message from a mail user agent (or another mail transfer agent) and either delivers it or forwards it.
mail user agent
(MUA) A program that allows the user to write and read email messages. Outgoing mail goes from the mail user agent to the mail transfer agent, and on to the addressee. Incoming messages are retrieved from the mail transfer agent. (Single-user machines more often pick up mail using POP).
Mail Users' Shell
A mail user agent for MS-DOS and Unix.
mailbot
A program which automatically delivers information via electronic mail.
mailbox
A box that holds incoming mail; a box for electronic mail is a file where mail messages are stored until the addressee opens and reads them.
mailer
A program that delivers electronic mail.
mailing list
An email discussion forum. Participants subscribe to a list, receive copies of messages sent by other members, and can email their own comments. In some mailing lists there is a moderator who receives all mail, screens it, and decides which messages to pass on. Unmoderated lists simply redirect all mail received to the list of recipients. Mailing lists may be highly technical, or social and recreational. The advantage of mailing lists over public Usenet groups is that the discussion is limited to highly interested and committed participants, and therefore more focused.
main distribution frame
(MDF). The storage space which contains the hardware for the main hub of a network.
main storage
Memory; also called main memory. The working space used by the computer to hold the program that is currently running, along with the data it needs, and to run programs and process data. The main memory is built from RAM chips. The amount of memory available determines the size of programs that can be run, and whether more than one program can be run at once. Main memory is temporary, and is lost when the computer is turned off. It is distinguished from more permanent internal memory (ROM) which contains the computer's essential programs, and storage (the disks and tapes which are used to store data).
mainframe
A “mainframe” originally meant the cabinet containing the central processor unit of a very large computer. After minicomputers became available, the word mainframe came to refer to the large computer itself. The older computers used many large vacuum tubes and generated a lot of heat, thus requiring specially air-conditioned rooms. A single computer might have hundreds of users at a time. Today, because the large vacuum tubes have given way to transistors, a desktop personal computer can have as much power as a mainframe computer that once filled a whole room. Mainframes in use now often have smaller computers as front end processors.
mainframe
This is a large and expensive computer with the ability to support hundreds or thousands of users simultaneously.
mainframe computer
A “mainframe” originally meant the cabinet containing the central processor unit of a very large computer. After minicomputers became available, the word mainframe came to refer to the large computer itself. The older computers used many large vacuum tubes and generated a lot of heat, thus requiring specially air-conditioned rooms. A single computer might have hundreds of users at a time. Today, because the large vacuum tubes have given way to transistors, a desktop personal computer can have as much power as a mainframe computer that once filled a whole room. Mainframe computers in use now often have smaller computers as front end processors.
major release
A release of new software or a software update which contains important changes.
Majordomo
A UNIX mailing list processor used to manage email discussion lists.
make
In Unix and Unix-like operating systems, “make” is a command that creates a machine-language program by compiling source files to produce a group of object files, and then linking the object files together. A makefile contains the commands that control this process.
makefile
A makefile is a script through which the programmer gives the computer instructions on how to build a particular program using the “make” command.
mal-ware or malware
Viruses, worms, Trojan horses, and other malicious programs.
male connector
A plug that fits into a “female” counterpart, or socket.
malfunction
The inability of a system or component to perform a required function; a failure.
malicious logic
Logic (hardware or software) that is purposely introduced into a system with harmful intent.
MAN
Metropolitan Area Network. A network that serves a metropolitan area. Compare LAN and WAN.
Management Information Base
(MIB). A database containing ongoing information and statistics on each device in a network, used to keep track of each device's performance and make sure all are functioning properly. MIBs are especially used with SNMP.
Management Information System
(MIS) A computer system for a business or other organization which collects and analyzes data from all departments, and is designed to provide an organization's management with up-to-date information (such as financial reports, inventory, etc.) at any time.
Management Information Systems
The study of effective systems for the development and use of information in an organization.
Manchester Automatic Digital Machine
(MADAM). One of the first chess-playing machines, developed by Alan M. Turing (1912-1954) in 1950. It was not very smart.
MANIAC
Mathematical Analyzer, Numerator, Integrator, and Computer. A high-speed computer built at the Los Alamos Scientific Laboratory in the late 1940s – early 1950s, which was used in the development of the hydrogen bomb.
mantissa
1. In a floating point number, the numeric value which is multiplied by the radix raised to the power of its exponent; for example, in 145,000 = 145 x 10^3, 145 is the mantissa, 10 is the radix, and 3 is the exponent. 2. The non-negative fractional part of a logarithm; the part of the logarithm on the right of its decimal point.
manual feed
Putting one sheet of paper into the printer at a time, by hand, instead of using the sheet feeder. The printing setup on a computer usually allows a choice between using the sheet feeder and manual feed. Manual feed is often used for large sheets of paper or nonstandard paper.
manularity
A measure of the amount of manual labor required to do a task; can be used to calculate the benefit that would result from automating the task. For example, collating a book by hand has a higher manularity than using an automatic collator.
MAPI
Messaging Application Programming Interface. A program interface that enables a user to send and receive email from within any MAPI-compliant application by means of the Microsoft Mail messaging system. If two applications are MAPI-enabled, they can share email messages with each other. Applications that can use MAPI include word processors, spreadsheets, and graphic applications. See also API.
marching ants
In paint and draw programs, when an object is selected, it is displayed on the screen with moving black and white dashes around its border. Some users call this effect “marching ants.”
Marconi, Guglielmo
An Italian inventor (1874-1937) who discovered that radio signals could be sent over long distances.
margin
The space between text and the edge of the page. Most word processors and page layout programs provide a way of adjusting the margins.
mark
1. A symbol or sign used to record something. 2. To select an item or group of items. 3. A 1 bit.
Mark 1
The first full-sized digital computer, developed in 1944 by Howard Aiken at Harvard University.
Markov chain
A random process in which the probability that a certain future state will occur depends only on the present or immediately preceding state of the system, and not on the events leading up to the present state.
Markov process
A random process similar to a Markov chain, except the states are ongoing; for example, Brownian motion.
Markov, Andrei
A Russian mathematician (1856-1922), after whom the Markov process and Markov chains were named.
markup
The process of adding coding to a text document which gives instructions for layout, type styling, placement of graphics, or other information which will be interpreted by the system used to read the document. See markup language.
markup language
A language that has codes for indicating layout and styling (such as boldface, italics, paragraphs, insertion of graphics, etc.) within a text file; for example SGML and HTML.
marquee select
In graphics programs, a way of selecting more than one item at a time. When several items are selected together, they are highlighted by a line of moving dashes around the outside which gives the impression of a theater marquee.
Martian
A joke term referring to a data packet that shows up on the wrong network, misrouted because of an error in addressing or having been sent to a nonexistent address.
MARVEL
Machine-Assisted Realization of the Virtual Electronic Library (U.S. Library of Congress).
mass storage
A large-capacity backup storage such as an external hard disk or magnetic tape.
massage
To transform a file from one form into another. Used to describe various ways of processing data or files; sometimes refers to the editing of text or graphics files.
master
A computer which controls another computer or a peripheral.
master page
A template that sets up certain design elements that will appear on every page of a printed document, such as headers, footers, logos, or borders.
math coprocessor
A circuit inside a computer that handles high-speed floating point arithmetic operations. It may be on its own separate chip, or on the CPU chip. The math coprocessor is not used with every program, but programs that contain instructions for the math coprocessor can do arithmetic operations much more quickly than programs that use only the CPU. The main use for a math coprocessor is in CAD and spreadsheet applications. Some software is designed to use a math coprocessor and will not run at all if a coprocessor is not installed. Other programs are designed to use the coprocessor if it is there and to use the CPU otherwise. The math coprocessor is also called a floating point coprocessor or floating point unit (FPU).
Mathematical Analyzer, Numerator, Integr
(MANIAC). A high-speed computer built at the Los Alamos Scientific Laboratory in the late 1940s – early 1950s, which was used in the development of the hydrogen bomb.
Mathematics Markup Language
(MathML). An XML application for including mathematical and scientific expressions on Web pages.
MathML
Mathematics Markup Language. An XML application for including mathematical and scientific expressions on Web pages.
matrix
An array of elements in rows and columns which effectively organizes data in the form of a table.
Matrox Millenium
A 64-bit PCI (Peripheral Component Interconnect) video card with 2MB or 4MB WRAM. It supports video and MPEG.
Matrox Mystique
A 64-bit PCI (Peripheral Component Interconnect) video card with 2MB or 4MB SGRAM. It supports video and MPEG.
maximize
To enlarge a window to full size, in a graphical user interface. In Windows, this is done by clicking the mouse on "maximize"; in a Macintosh file, by clicking on the little box in the upper right-hand corner. Opposite of minimize.
maximum transmission unit
(MTU). The largest unit of data that can be transmitted on any particular physical medium.
MB
1. Megabyte: 1,048,576 bytes or 1,024 kilobytes. Used to measure computer memory. Sometimes used to mean 1 million bytes or 1,024,000 bytes (1,000 kilobytes). 2. Motherboard.
Mb
megabit. 1. (Also mbit or Mbit). 1,048,576 (216) bits, or 1024 kilobits. A measurement of the capacity of memory chips. Also used to mean one million bits. See megabyte. 2. Sometimes Mb is used for megabyte.
MBone
Multicast Backbone. A network of Internet sites that supports Internet Protocol multicasting for a limited number of users. MBone provides a faster technology than the Internet for transmitting real-time audio and video programs, and for videoconferencing. The Rolling Stones made history with the first major multicast concert on the MBone.
mbps
(Also Mbps) Megabits per second (million bits per second). Used to measure the rate of information transfer.
MBps
Megabytes per second (million bytes per second).
MC
Machine Code. The language which is actually read and understood by the computer.
MC92100
Also called Scorpion. A graphics and digital video encoder chip which makes adds Internet browsing and other interactive features to a television set. The MC92100 chip can be used with existing sets or new products. It can be used with set-top boxes and DVDs. Users will be able to display multiple windows on the screen, watching television and browsing the Internet at the same time.
MCF
Meta Content Framework. An XML application proposed by Netscape Communications, which provides a standardized way to describe files or collections of data. See metadata, RDF, and XML.
MCGA
Monochrome/Color Display Adapter. A monochrome video system for early IBM PCs, which displayed very clear text but no graphics.
MCI Mail
An online service that provides electronic mail, fax, and Telex. In addition to ASCII text messages, files can be transmitted using the Xmodem, Ymodem, Kermit and Zmodem protocols, allowing the sending of binary files such as word processing documents, spreadsheets, etc. For security, mail from one MCI Mail account to another stays within the system, unlike on the Internet, where mail “hops” from one computer to another. MCI Mail also provides overnight courier delivery, receipt notification, electronic forms, and a gateway to Dow Jones News Retrieval database service.
MCSD
Microsoft Certified Solution Developer.
MCSE
Microsoft Certified Systems Engineer
MD DATA drive
A drive for Sony 140-megabyte data storage cartridges, which can also read Sony MiniDiscs.
MD5
A one-way hash algorithm used to create a message digest for digital signatures. MD5 is used with 32-bit machines and can be used when large messages have to be compressed in a secure format before a private key is used.
MDF
Main Distribution Frame. The storage space which contains the hardware for the main hub of a network.
Mead Data Central
An online service offering news and legal information.
mean time between failures
(MTBF). A figure that gives an estimate of the reliability of a piece of equipment. The higher the MTBF, the longer the equipment should last. For example, if the MTBF is 10,000 hours, the equipment should run, on the average, for 10,000 hours before failing.
mean time to failure
(MTTF). The approximate amount of time expected before a system or component will fail; see mean time between failures.
mean time to recovery
(MTTR). The average amount of time a functional unit will spend in corrective maintenance over a given period of time.
mean time to repair
(MTTR). The average amount of time needed to repair a failed unit.
meatware
Animal systems, as opposed to computer hardware or software. Used most often to compare the human biological system, controlled by its nervous system, to a computer system controlled by its central processing unit.
mechanical mouse
mechanical mouse
A mouse that operates by mechanical means; a rubber ball rolls as the mouse is moved across a tabletop or mouse pad, and the rubber ball turns vertical and horizontal wheels inside the mouse. The wheels, called encoders, have tiny metal contact points on their rims, which touch a contact bar as they turn. The contact bar sends electrical signals to the computer. The location of the mouse is established by how many times the contact points have touched the bars, the direction in which the wheels are turning, and the ratio between the number of signals from the vertical and horizontal encoders. The mechanical mouse is different from the optical mouse, which uses a beam of light to tell where it is.
medical informatics
The use of computers in medical research, medical education, and clinical medicine.
medium access control or media access co
(MAC). On a local area network, the control of which device has access to the transmission medium at a particular time.
medium access control protocol
(MAC protocol). In a local area network, the protocol that determines which device has access to the transmission medium at a given time.
medium access control sublayer
(MAC sublayer). The lower sublayer of the data link layer, which uses the network's physical layer to provide services to the logical link control (LLC). The functions of the MAC sublayer vary according to the topology of the network.
medium frequency
(MF). Electromagnetic frequencies in the range of 300 to 3000 kiloherz.
medium interface connector
(MIC). A type of connector for fiber-optic cable that uses a plug and socket and has been used with FDDI and local area networks.
MEDLARS
An online medical database from the National Library of Medicine, Bethesda, Maryland.
meg
1. Mega, or million (M). Sometimes means 1,048,576. 2. Megabyte.
mega-
1. Prefix meaning one million or 106. 2. Also used to mean 230.
megabit
(Mb, mbit or Mbit) 1,048,576 (216) bits, or 1024 kilobits. A measurement of the capacity of memory chips. Also used to mean one million bits. See megabyte.
megabyte
(MB, mb, Mbyte, M-byte) 220 bytes = 1,048,576 bytes or 1,024 kilobytes. Used to measure computer memory. Sometimes used to mean 1 million bytes or 1,024,000 bytes (1,000 kilobytes). See megabit.
megabytes
(MB, mb, Mbyte, M-byte) Each megabyte is 220 bytes = 1,048,576 bytes or 1,024 kilobytes. Megabytes are used to measure computer memory. Sometimes a megabyte means 1 million bytes or 1,024,000 bytes (1,000 kilobytes). See megabit.
megaflops
Million floating-point operations per second. A unit used to measure the performance of computers that do calculation.
megahertz
(MegaHertz , MHz). Millions of cycles per second. The unit of frequency used to measure the clock speed of a computer.
megapixel image
In graphic design, an image containing a very large number of pixels, a million or more. Megapixel images have a lot of detail and make very large files.
MEM
Microelectromechanical.
memory
Also called main memory. The working space used by the computer to hold the program that is currently running, along with the data it needs, and to run programs and process data. The main memory is built from RAM chips. The amount of memory available determines the size of programs that can be run, and whether more than one program can be run at once. Main memory is temporary, and is lost when the computer is turned off. It is distinguished from more permanent internal memory (ROM) which contains the computer's essential programs, and storage (the disks and tapes which are used to store data).
memory cache
A memory bank between the main memory and the CPU, which enables the computer to read data and execute instructions faster. The memory cache is static RAM (SRAM); main memory is dynamic RAM (DRAM). See cache and disk cache.
memory capacity
The amount of space available for storing data in memory, designated in bytes.
memory dialing
A feature of a telephone that allows numbers to be stored for quick dialing by pressing one or two buttons.
memory effects
A problem with nickel cadmium batteries in which the battery remembers how full it was when it was last charged, and doesn't go past that point the next time. Because of this the battery must be completely drained before recharging to get the longest charge.
memory expansion
Adding additional memory to a personal computer by means of expansion cards.
memory expansion option
The option of adding additional memory to a personal computer by means of expansion cards.
memory management
Strategies for providing sufficient memory to all the processes in a computer system, performed by the memory management unit (MMU).
memory management unit
(MMU). A hardware device which translates virtual addresses into physical addresses and is used to manage virtual memory.
memory protection
A system used to prevent one program from corrupting another program running at the same time, and to prevent corruption of the operating system. A hardware memory management unit and special programs are used to ensure that instructions within one program are not able to accidentally influence another program. Windows NT and most versions of UNIX have memory protection. MacOS 8 will have it.
memory resident
Remaining in memory in order to be available for immediate use.
Memphis
The original code name for Windows 97, which was later renamed Windows 98 when Microsoft realized that it was going to miss its target 1997 release date.
menu
A onscreen list from which the user may choose an operation to be performed. Items from the menu may be selected by keyboard commands or by pointing with a mouse.
menu bar
A bar across the top of the computer screen or window, which has the names of available pull-down menus, such as “File”, “Font”, “Window”, etc. Pressing the mouse on a menu bar item makes its pull-down menu appear.
menu-driven
Having an interface that uses menus, as opposed to a command-line interface.
menu-driven interface
A user interface that uses menus to communicate with the computer. Rather than having a single line where a command must be typed in, the user has a list of items to choose from, and can make selections by highlighting one. This kind of interface is easier to use than a command-line interface, but does not have all the visual elements of a graphical user interface.
message
1. In communications, a message is information transmitted via a network. 2. In object-oriented programming, a call for one of an object's methods.
Message Handling Service
(MHS). Novell messaging software.
Message Handling System
(MHS). The ISO Message-Oriented Text Interchange Standard; called X.400 by ITU-T. The OSI electronic mail system, comprised of message user agents, message transfer agents, message stores, and access units.
message sink
In a communication system, the part that receives messages.
message transfer agent
(MTA). A mail agent, used to store and transfer messages in the X.400 Message Handling System.
Messaging Application Programming Interf
(MAPI). A program interface that enables a user to send and receive email from within any MAPI-compliant application by means of the Microsoft Mail messaging system. If two applications are MAPI-enabled, they can share email messages with each other. Applications that can use MAPI include word processors, spreadsheets, and graphic applications. See also API.
Meta Content Framework
(MCF). An XML application proposed by Netscape Communications, which provides a standardized way to describe files or collections of data. See metadata, RDF, and XML.
Meta tag
An identifying tag for HTML or XML documents that can be viewed in HTML or XML source. The tag allows information such as keywords that identify content, the author’s name and other descriptive details.
meta-searcher
A regular search engine allows a user to search a single database. A meta-searcher is a front end that passes each query to multiple search engines.
MetaCard
A hypertext system for Unix and the X Window System, which is similar to HyperCard.
MetaCrawler
An Internet multisearch engine (http://www.metacrawler.com/index.html); it searches nine other search engines (Lycos, Open Text, Alta Vista, Excite, WebCrawler, InfoSeek, Inktomi, Yahoo, and Galaxy).
metadata
Data about data; for example, tags that indicate the subject of a WWW document.
metafile
A file format designed for exchanging graphical data between different application programs or different machines, often as a bitmap.
metalanguage or meta-language
A language that is used to specify the rules for other languages. XML is an example; it provides a set of rules for constructing markup languages.
metaprogram
A program used to create or modify other programs.
meter
The basic unit of length in the metric system: the distance traveled by light in a vacuum in 1/299,792,458 second; about 39.37 inches.
metric
1. Referring to the metric system, a decimal system of weights and measures based on the meter and the kilogram. 2. Any standard of measurement.
metropolitan area network
(MAN) A network that serves a metropolitan area. Compare LAN and WAN.
MF
Medium Frequency. Electromagnetic frequencies in the range of 300 to 3000 kiloherz.
MFC
1. Microsoft Foundation Classes. A class library for 32-bit Windows development (Windows 95 and Windows NT). 2. Miniature Forward Error Corrector. A hardware device that is inserted between a computer and modem to enable forward error-free communication without retransmission. The MFC encodes data for transmission, adding redundant bits. At the receiving end, the data is decoded, and errors are detected and corrected. 3. Multi-Function Center. A combination laser printer, fax, copier, scanner, fax, and message center from Brother.
MFLOPS
A benchmark that measures megaflops (million floating-point operations per second).
MHS
1. Message Handling System. The ISO Message-Oriented Text Interchange Standard; called X.400 by ITU-T. The OSI electronic mail system, comprised of message user agents, message transfer agents, message stores, and access units. 2. Message Handling Service. Novell software for messaging.
MHz
(MegaHertz or megahertz). Millions of cycles per second. The unit of frequency used to measure the clock speed of a computer.
MI/X
A free X Window server for both 680×0 and Power Macs.
MIAW
Movie in a Window. Terminology used in Macromedia Director.
MIB
Management Information Base. A database containing ongoing information and statistics on each device in a network, used to keep track of each device's performance and make sure all are functioning properly. MIBs are especially used with SNMP.
MIC
Medium Interface Connector. A type of connector for fiber-optic cable that uses a plug and socket and has been used with FDDI and local area networks.
Michael's Disk Benchmark
A simple disk I/O benchmark for Windows 95 or Windows NT, distributed as shareware.
mickey
A unit by which mouse movement is measured: 1/200th of an inch.
MICR
Magnetic Ink Character Recognition. A character recognition system used on bank checks; special ink and characters are used, which can be magnetised for automatic reading.
micro
1. 10-6, one millionth. 2. A microprocessor or microcomputer.
micro-
A prefix meaning one millionth (10-6).
microbrowser
An Internet browser designed for use with a wireless handheld device such as a mobile phone. Microbrowsers have small file sizes to accommodate the low memory available to handheld devices and the the low-bandwidth constraints of the wireless-handheld networks.
microchip
Also called microelectronic or integrated circuit. A microelectronic device comprising many miniature transistors and other electronic components on a single thin rectangle of silicon or sapphire, approximately 1/16″ to 5/8″ on a side, and 1/30″ thick. A microchip can contain dozens, hundreds, or millions of electronic components. To make a microchip, impurities are added to the supporting material, or substrate, in specific places to create P-type and N-type regions; then by projecting light onto light-sensitive chemicals, polysilicon or aluminium tracks are etched into the top 1/1000″ of the substrate to make the electronic circuits. The chips come in analog, digital and hybrid types. Compared with earlier technology, microelectronics are faster, more compact, more energy-efficient, and cheaper to manufacture. The most complete integrated circuit is a microprocessor: a computer on a single chip.
A microprocessor which operates as an embedded system (a computer that forms part of a larger machine of some other type).
microelectromechanical system
A system that integrates microelectronics with mechanical parts.
microelectronics
1. The branch of electronics dealing with the miniaturization of components and circuits. 2. Devices or circuits produced using microelectronics.
MicroEmacs
A simple text editor which has versions for most personal computers and for many other computers.
microfiche
A sheet of microfilm which has microimages in a grid pattern.
microfilm
A high resolution film on which photographic records are kept of documents or other material, in greatly reduced size. Microfilm makes it possible to store a great amount of material in a small amount of space.
micron
One millionth of a meter, which is about 1/25,000 of an inch. A measurement used in microelectronics.
microprocessor
A computer with its entire CPU contained on one integrated circuit.
The first microprocessor was created by Intel. The creation of microprocessors was the breakthrough that led to the development of personal computers. Microprocessors have, over time, acquired more and more of the features of large computers.
microsecond
One millionth (10-6) of a second.
Microsoft Access
A database program for Microsoft Windows that can be used to create forms, reports, and graphs.
Microsoft Basic
(MS-BASIC). Formerly called GWBasic and QBASIC. A form of BASIC from Microsoft, originally developed by Bill Gates.
(MSN). An online information service sponsored by Microsoft, similar to America Online and CompuServe. The Microsoft network (http://www.home.msn.com/) has discussion groups, electronic mail, Internet access, and information on Microsoft products.
Microsoft Windows
User interface software with windows released by Microsoft in 1985 to run with MS-DOS.
Microsoft Windows 1
The first version of Microsoft Windows, which came out in 1985. It was able to display tiled windows.
Microsoft Windows 2
The second version of Microsoft Windows, which improved on Windows 1 by allowing overlapping windows and icons and supporting expanded memory. It was released in 1987. It was later named Windows/286.
Microsoft Windows 3.0
The first version of Microsoft Windows that gained wide popularity. It is able to manage larger amounts of memory than previous versions, and can run 16-bit DOS and Windows applications. Many applications were developed for Windows 3.0.
Microsoft Windows 3.1
An improvement on Windows 3.0, which includes multimedia capability, TrueType fonts, and Object Linking and Embedding (OLE). With the Win32s extension, Windows 3.1 can run 32-bit applications. Windows 3.1 is the stand-alone Windows; there is also Windows for Workgroups 3.1.
Microsoft Windows 3.11
The last upgrade to Windows 3.1.
Microsoft Windows 95
An operating system with graphical user interface from Microsoft, which can run 32-bit applications. Windows 95 was a major upgrade from earlier versions of Windows up to Windows 3.1, which simply provided a graphical user interface for DOS. Some features of Windows 95 are Plug and Play capability, threading, pre-emptive multitasking, and built-in networking. The user interface has icons and folders similar to Macintosh, and allows the use of long file names. The minimum requirements for a computer to run Windows 95 are an 80386 or Pentium CPU and at least 8 megabytes of RAM.
Microsoft Windows 98
An advancement over Windows 95. Windows 98 supports new technologies including FAT32, AGP, MMX, USB, DVD, and ACPI. Another new feature is the Active Desktop, which integrates the Web browser,Internet Explorer, with the operating system. To the user of Active Desktop, there is no difference between accessing a document local to the user’s hard disk and accessing a document from a Web server on the other side of the world.
Microsoft Windows for Workgroups
(WFW). A version of Windows 3.1 which is specifically designed to be used with a network.
Microsoft Windows for Workgroups 3.11
An upgrade to Windows for Workgroups 3.1 which includes 32-bit file access and the ability to send and receive faxes.
Microsoft Windows New Technology
Microsoft Windows NT. A 32-bit operating system from Microsoft for high-end workstations, servers, and networks. It has built-in networking, pre-emptive multitasking, multi-threading, memory protection, and fault tolerance. It can be used on PCs and other types of computers, including DEC Alpha. Windows NT supports the Unicode character set, which allows more characters than standard ASCII. The minimum requirements for Windows NT are an 80386 processor, and at least 12 megabytes of RAM. Windows NT has become especially popular as a server because of its extra security features.
Microsoft Windows NT
Microsoft Windows New Technology. A 32-bit operating system from Microsoft for high-end workstations, servers, and networks. It has built-in networking, pre-emptive multitasking, multi-threading, memory protection, and fault tolerance. It can be used on PCs and other types of computers, including DEC Alpha. Windows NT supports the Unicode character set, which allows more characters than standard ASCII. The minimum requirements for Windows NT are an 80386 processor, and at least 12 megabytes of RAM. Windows NT has become especially popular as a server because of its extra security features.
Microsoft Windows/286
The second version of Microsoft Windows, originally called Windows 2, which improved on Windows 1 by allowing overlapping windows and icons and supporting expanded memory. It was released in 1987.
Microsoft Windows/386
A version of Microsoft Windows that followed Windows/286, released in 1987. It added the ability to run several applications at a time, by using extended memory.
Microsoft Word
A Microsoft word processing program for DOS, Windows and Macintosh.
MicroVAX Unit of Performance
(MicroVUP). A unit of measurement of microcomputer performance. One VUP equals the performance of a VAX 11/780; the MicroVUP has been used to rate VAX workstations.
MicroVUP
MicroVAX Unit of Performance. A unit of measurement of microcomputer performance. One VUP equals the performance of a VAX 11/780; the MicroVUP has been used to rate VAX workstations.
mid-level network
The networks on the second level of the Internet hierarchy, which connect the stub networks to the backbone networks. Also called a regional network.
middle letter row
The center letter row (row of letter keys) on a keyboard.
middle-endian
Neither big nor little-endian, a middle-endian order could be 3-4-1-2.
middleware
Software that provides a link between disparate applications.
MIDI
Musical Instrument Digital Interface. A way of communicating instructions for playing music from one electronic device to another; for example, from a synthesizer to a computer to a musical instrument. MIDI includes hardware (the electronic instruments and the interface between devices) and software (the set of rules for encoding and transfer of sound information). With MIDI, a musician can use a keyboard to simulate the sounds of many different instruments, plus add special effects. A MIDI file does not store sound as a wave file does; rather, it stores information on how to create the sounds. Some of the parameters indicated by a MIDI file are pitch, loudness, timbre, and length of a note. Because MIDI instructions resemble a musical score, a MIDI file can be edited in many ways: for example, the tempo can be changed, one instrument can be changed to another, or the whole composition can be transposed to a different key. MIDI files take up less storage space than files that store actual sounds.
MIDI file
Musical Instrument Digital Interface file. A set of instructions for a computer or synthesizer to play a certain musical composition. The MIDI file does not include actual sounds, but information on how to make the sounds. The MIDI instructions include the notes played, length of notes, instruments, volume, rhythm, etc. MIDI files on the Internet can be played with the help of a media player application, such as Crescendo.
MIDI patch
One of the channels in a MIDI device. The General MIDI Standard (GMS) assigns specific instruments to specific MIDI patch locations.
MIDI sequencer
Hardware or software that is used to create, play, or edit MIDI files.
midrange computer
A minicomputer; does not include minicomputers which are single-user workstations.
milli-
Prefix meaning one thousandth or 10-3.
milliard
10^9 (Europe); equivalent to a billion in the U.S.
millimeter
One thousandth of a meter, or .039 inch.
millisecond
(ms) One thousandth of a second.
millivolt
(MV). One thousandth of a volt.
Milnet
MILitary NETwork. Milnet was originally part of ARPAnet, and was split off in 1984 as a network for the military, leaving the rest of ARPAnet as a research network.
MIMD
Multiple Instruction/Multiple Data. A kind of parallel processor in which many operations are performed on different data.
MIME
(Multipurpose Internet Mail Extensions). Extensions to the Internet mail format that allow it to carry multiple types of data (binary, audio, video, graphics, etc.) as attachments to e-mail messages.
Massachusetts Institute of Technology.
MJPEG or M-JPEG
Moving JPEG. A moving image which is made by storing each frame of a moving picture sequence in JPEG compression, then decompressing and displaying each frame at rapid speed to show the moving picture. M-JPEG does not use interframe coding as MPEG does. Sometimes called Motion JPEG.
mkdir
A UNIX command to create a directory (make directory).
MMCD
Multimedia Compact Disc. A CD-ROM that can hold 4.7 GB of data, including video.
MMF
Make Money Fast. A notorious early Usenet post encouraged people to spam a chain letter with the title Make Money Fast. MMF now refers to all similar exploitative schemes.
MMU
Memory Management Unit. A hardware device which translates virtual addresses into physical addresses and is used to manage virtual memory.
MMX
MultiMedia Extensions. Technology developed by Intel to improve multimedia performance on Intel processors. MMX makes it possible to enhance multimedia operations (video, audio, communications, and graphics) without add-on sound cards or video cards. MMX technology is based on SIMD (Single Instruction, Multiple Data) technique; to take advantage of MMX, the software used with it must be written for the MMX instructions. MMX will be used on the Intel P55C Pentium processor and P6 family processors, the Advanced Micro Devices (AMD) K6 family of processors, and the Cyrix M2 processor.
mnemonic
A memory aid; a word or expression which isdesigned to be easier to remember than what it represents. Mnemonics are used in programming; for example, assembly language instructions are mnemonics for the binary patterns of machine code.
MO disk
Magneto-optical disk. A plastic or glass disk coated with a chemical (often TbFeCo) with special properties which make it rewritable. A combination of magnetic and optical methods are used to write data to the disk. A high-intensity laser heats the material up to its Curie point, the temperature at which molecules can be realigned by a magnetic field. A magnet is used to make changes in polarity which remain after cooling. The disk is read by directing a low-intensity laser at the disk and interpreting variations in its reflected light, which result from differences in polarity of the stored magnetic field.
MO7
Magneto-Optic7. A rewritable optical disk technology that holds 6GB on a 12 cm disk. MO7 changed its name to Advanced Storage Magneto-Optical technology.
mobile telephone switching office
(MTSO). A central office for mobile telephone service, with switches and computers that connect all cell sites in a service area and keep track of all calls.
mobo
Slang for motherboard.
mockingbird
A kind of Trojan Horse that imitates a system in order to intercept communications from users logging in and thereby acquire passwords and other information.
mode
An operational state of a computer or system in which certain functions can be performed. For example, when a word processor is in insert mode, any letters typed will insert themselves wherever the cursor is, moving aside all type to the right. When the mode is switched to overwrite mode, each letter typed will replace the letter to the right of the cursor.
modem
A peripheral device that connects computers to each other for sending communications via the telephone lines. The modem modulates the digital data of computers into analog signals to send over the telephone lines, then demodulates back into digital signals to be read by the computer on the other end; thus the name “modem” for modulator/demodulator. Modems are used for sending and receiving electronic mail, connecting to bulletin board systems, and surfing the Internet. There are standards to ensure that modems made by different manufacturers can communicate with each other. Modems communicating with each other must use the same speed.
moderator
A person who receives the email messages for a moderated mailing list or newsgroup, screens all submissions, and decides which ones to pass on to the other members.
module
A self-contained functional unit which is used with a larger system. A software module is a part of a program that performs a particular task. A hardware module can be a packaged unit that attaches to a system.
moire pattern
A radiating curved pattern seen when two geometrically regular patterns (as two halftone screens) are superimposed. A moire pattern can result from scanning or rescreening a halftone, which puts a screen over another screen. Usually moire patterns are not wanted because they interfere with viewing the image. Sometimes this effect can be controlled by adjusting the angle of the halftone, or refining the image with a photo editing program. A moire pattern can also result from problems with the computer monitor.
monadic operation
An operation with only one operand (entity that is operated on).
monitor
Also called a display. A device that displays text and graphics generated by a computer. Desktop monitors are usually cathode-ray tubes, and laptop monitors are usually liquid crystal display. A monitor can be monochrome (black and white) or color. Color monitors may show either digital or analog color.
monitor port
A port that is used to connect a monitor to the computer.
monoalphabetic cipher
A cipher in which only one substitution or transposition is used.
monochrome
Monochrome means one color, and is used to refer to a black and white monitor, or a monitor that has one foreground color and one background color (such as green and black). Grayscale displays have more shading variation, but are sometimes called monochrome.
Monochrome/Color Display Adapter
(MCGA). A monochrome video system for early IBM PCs, which displayed very clear text but no graphics.
monospaced font
Also called fixed-pitch type. A font in which each character takes up the same width, like the characters on a typewriter. In a monospaced font, an i takes up as much horizontal space as an m (more blank space is left around the thin letters). The opposite is proportional spacing, (proportional-pitch type), in which each letter has a spacing proportional to its width.
MOO
Object Oriented Multi User Dungeon. MOOs use object-oriented programming to add dimension, whereas MUDs are text-based games.
MooreÕs Law
A law that states that the logic density of silicon has approximately doubled every year since the invention of the silicon chip. This means the amount of information that can be stored on a chip of the same size doubles every year. Another formulation is that the speed of new computers doubles every year and a half.
Moria
A popular Dungeons and Dragons-style simulation game, named after J.R.R. Tolkien's Mines of Moria.
morphing
A gradual animated transformation from one image into another, partially accomplished by moving certain points in the first image to corresponding points in the second image, in stages.
Morse code
A code in which each letter is represented by a pattern of dots and/or dashes, developed by Samuel Morse in the 1800s. The signals are sent by sound, light beams, or electric pulses. A dot is a signal of short duration, and a dash is a signal of longer duration. Morse code was used to send telegraph messages before the invention of the telephone and has been used in many other ways, such as emergency and wartime communications. It was originally in English, but has been adapted to other languages with different characters.
Mosaic
The first World Wide Web browser, created by the University of Illinois National Center for Supercomputing Applications (NCSA). Mosaic was the breakthrough that caused the World Wide Web to become widely used, as it was the first software that provided a multimedia graphical user interface for the Internet. It is available for UNIX, Windows, and Macintosh.
most significant bit
(MSB). In a binary number, the bit that is farthest to the left, and has the greatest weight.
most significant digit
The non-zero digit which is farthest to the left in a number, and has the greatest value.
The main circuit board inside a computer, which contains the central processing unit, the bus, memory sockets, expansion slots, and other components. Additional boards, called daughter boards, can be plugged into the motherboard.
The path that an animated object will follow (in computer animation).
Motion Picture Experts Group, Audio Laye
(MP3). A popular music download format. MP3 produces CD-quality music in a compressed file that can be transferred quickly, and played on any multimedia computer with MP3 player software.
Motorola, Inc.
A company in Schaumberg, Illinois, which manufactures semiconductors, communications devices such as cellular telephones and two-way radios, and many other electronics products. Motorola was one of the developers of the PowerPC.
Mount
Making a physical disk, or a remote file avilable for access locally.
mouse
A pointing device that is used to move a cursor on the computer screen, and make various operations possible such as typing, drawing, editing text and graphics, opening and closing files, and giving other commands. The wire connecting it to the computer or keyboard looks like a mouse's tail.
A mouse is moved over a flat horizontal surface, usually a rubber mouse pad, and its position is read by the computer. The original mouse has a button which the user clicks or holds down to place the cursor; now many models have more than one button.
mouse ahead
To input commands with the mouse faster than the computer can follow the commands. The computer will remember a few mouse moves ahead and catch up when it has the chance.
mouse around
To look around on the Internet or another network.
mouse pad
A rubber pad that sits next to the keyboard and provides a smooth surface on which to move a mouse.
mouse pointer
The little symbol on the screen that is moved with the mouse. Within text, the mouse pointer appears as a cursor, but it changes shape depending on its location on the screen and the program in use. The mouse pointer can take the form of a hand, an arrow, a cross, and other symbols. It is also called a mouse cursor.
mouse port
The computer socket provided for plugging in a mouse.
Moving JPEG
(M-JPEG). A moving image which is made by storing each frame of a moving picture sequence in JPEG compression, then decompressing and displaying each frame at rapid speed to show the moving picture. M-JPEG does not use interframe coding as MPEG does. Sometimes called Motion JPEG.
Moving Pictures Experts Group or Motion
(MPEG). 1. An ISO (International Standards Organization) group that sets standards for compressing and storing video, audio, and animation in digital form. 2. The standards set by this group. MPEG is a lossy compression method. MPEG-1 is a standard for CD-ROM video and audio. MPEG-2 is a standard for full-screen, broadcast quality video. MPEG-4 is a standard for video telephony.
Mozilla
Another name for Netscape Navigator.
MP3
MP3 stands for Motion Picture Experts Group, Audio Layer 3. A popular music download format. MP3 produces CD-quality music in a compressed file that can be transferred quickly, and played on any multimedia computer with MP3 player software. The technology creates sound files a tenth the size of standard CD music files with very little loss of sound quality. As a result, huge numbers of Internet users have taken to trading MP3 files back and forth, or posting them on download sites, often in violation of industry-owned copyrights. There are initiatives within the music industry to control the use of MP3 copies.
MP3 Player
Software that allows the user to listen to music or sound in MP3 format.
MP3 utility
A collection of tools for editing, sorting, and working with MP3s.
mpack
A UNIX compression program for MIME files.
MPC
Multimedia PC. A personal computer that has CD, sound, and graphics capabilities which meet standards specified by the MPC Marketing Council.
MPC2
The Multimedia Personal Computer (MPC) Marketing Council sets standards for multimedia computer systems. Certified products display the MPC2 symbol.
MPEG
Moving Pictures Experts Group. 1. An ISO (International Standards Organization) group that sets standards for compressing and storing video, audio, and animation in digital form. 2. The standards set by this group. MPEG is a lossy compression method. MPEG-1 is a standard for CD-ROM video and audio. MPEG-2 is a standard for full-screen, broadcast quality video. MPEG-4 is a standard for video telephony.
MPR II
Swedish low-emission standards for electromagnetic radiation. All computer monitors except the ones used in portable computers emit electromagnetic radiation (EMR). The MPR II guidelines define acceptable levels of EMR; some monitors are designed to meet these guidelines.
MPS
Multiprocessing System. A computer system that can run more than one program or set of instructions at a time, using two or more processors in the same computer, or two or more computers connected together.
MR
Modem Ready. A modem status signal indicated by a light on the modem, which means the modem is turned on and ready to operate.
ms
Millisecond — one thousandth of a second.
MS-BASIC
Microsoft Basic. Formerly called GWBasic and QBASIC. A form of BASIC from Microsoft, originally developed by Bill Gates.
MS-DOS
Microsoft Disk Operating System. A personal computer operating system from Microsoft, which is similar to IBM's PC-DOS. It is a single user system that runs one program at a time because of limited memory. Add-on memory boards can expand DOS capabilities. See also DOS.
MS-DOS application
An application designed to be run by the MS-DOS or DOS operating system. These applications can also be run under Windows and OS/2.
MSB
Most Significant Bit. In a binary number, the bit that is farthest to the left, and has the greatest weight.
MSCDEX.EXE
CD-ROM Extensions. An MS-DOS program to enable a PC to read CD-ROMs. It is loaded by AUTOEXEC.BAT. It has been used with DOS through Windows 3.1
MsgServ
An IRC bot which enables a user to leave a message for someone not currently signed on. The addressee receives the message upon login.
MSIE
MicroSoft Internet Explorer. Microsoft's popular web browser.
MSN
Microsoft Network. An online information service sponsored by Microsoft, similar to America Online and CompuServe. The Microsoft network (http://www.home.msn.com/) has discussion groups, electronic mail, Internet access, and information on Microsoft products.
MSXSL
Microsoft Extensible Style Language. Microsoft's XSL implementation. A language used in the creation of stylesheets for reading XML pages.
MTA
Message Transfer Agent. A mail agent, used to store and transfer messages in the X.400 Message Handling System.
MTBF
Mean Time Between Failures. A figure that gives an estimate of the reliability of a piece of equipment. The higher the MTBF, the longer the equipment should last. For example, if the MTBF is 10,000 hours, the equipment should run, on the average, for 10,000 hours before failing.
MTSO
(Mobile Telephone Switching Office). A central office for mobile telephone service, with switches and computers that connect all cell sites in a service area and keep track of all calls.
MTTF
Mean Time To Failure. The approximate amount of time expected before a system or component will fail; see mean time between failures.
MTTR
1. Mean Time To Recovery. The average amount of time a functional unit will spend in corrective maintenance over a given period of time. 2. Mean Time To Repair. The average amount of time needed to repair a failed unit.
MTU
Maximum Transmission Unit. The largest unit of data that can be transmitted on any particular physical medium.
mu
1. Multi-user. 2. A Greek letter used as a prefix, meaning micro- (millionth). When using only ASCII characters, it is represented by lowercase u, which looks the most like the Greek letter.
MUD
Multi-User Dungeon, Multi-User Dimension, or Multi-User Domain. A type of multi-player interactive game, played using Internet relay chat, with adventure, combat, magic, puzzles, and different locations to explore. MUDs can be played on the Internet or over a modem.
mudhead
A person who is addicted to MUD games.
MUG
Macintosh User Group.
Multi-Function Center
(MFC). A combination laser printer, fax, copier, scanner, fax, and message center from Brother.
multi-homed host
A computer that is connected to more than one physical data link. The data links it is connected to may or may not be attached to the same network.
Multi-User Dungeon
(MUD). Also called Multi-User Dimension, or Multi-User Domain. A type of multi-player interactive game, played using Internet relay chat, with adventure, combat, magic, puzzles, and different locations to explore. MUDs can be played on the Internet or over a modem.
multi-user shared hallucination
(MUSH). A type of MUD in which the players themselves can construct new rooms, or make objects and puzzles for each other.
multi-user system
An operating system that can support several people sharing the same computer at once.
multicast
Two-way communication between multiple sites, as in videoconferencing; or sending a communication from one site to a group of selected receivers. Multicasting differs from broadcasting in that a broadcast is sent to everyone who has the equipment or connection to receive it.
multicast backbone
(MBone). A network of Internet sites that supports Internet Protocol multicasting for a limited number of users. MBone provides a faster technology than the Internet for transmitting real-time audio and video programs, and for videoconferencing. The Rolling Stones made history with the first major multicast concert on the MBone.
Multichannel Multipoinbt Distribution Se
A wireless broadband technology used for Internet Access. MMDS uses both licensed and unlicensed channels that come in 6 mHz chunks, with transfer rates at 27 Mbps and 1 Gbps respectively.
Multics
Multiplexed Information and Computing Service. An early (1969) timesharing operating system, developed by MIT, GE, and Bell Laboratories, and introducing many new operating system features.
Multifinder
An enhanced version of the Macintosh Finder which added the capability of managing more than one application at a time. After this capability was no longer new on Macintoshes, the name was changed back to Finder.
multifunction peripheral
Multifunction peripherals, or MFPs, are multipurpose devices combining printing with faxing, color or black-white scanning, and phtocopying in one device. MFPs are popular among small office/home office (SOHO) owners because they are less expensive and use less space than would four separate devices. MFPs are also known as multifunction printers.
multimedia
Multimedia is communication that uses any combination of different media, and may or may not involve computers. Multimedia may include text, spoken audio, music, images, animation and video. The large amounts of data required for computer multimedia files makes CD-ROMs a good option for storage; but there are other ways of receiving multimedia communications, such as the World Wide Web. Multimedia programs are often interactive, and include games, sales presentations, encyclopedias, and more.
Multimedia Compact Disc
(MMCD). A CD-ROM that can hold 4.7 GB of data, including video.
MultiMedia Extensions
(MMX). Technology developed by Intel to improve multimedia performance on Intel processors. MMX makes it possible to enhance multimedia operations (video, audio, communications, and graphics) without add-on sound cards or video cards. MMX technology is based on SIMD (Single Instruction, Multiple Data) technique; to take advantage of MMX, the software used with it must be written for the MMX instructions. MMX will be used on the Intel P55C Pentium processor and P6 family processors, the Advanced Micro Devices (AMD) K6 family of processors, and the Cyrix M2 processor.
Multimedia Gulch
San Francisco’s challenge to Silicon Valley; a region of high-tech companies.
multimedia monitor
A monitor suitable for use with multimedia, with its own speakers.
multimedia PC
(MPC). A personal computer that has CD, sound, and graphics capabilities which meet standards specified by the MPC Marketing Council.
multimedia upgrade kit
A kit that contains hardware and software for upgrading a standard PC into a multimedia PC, including a CD-ROM drive, a sound card, speakers, cables, software, and sometimes selected multimedia CD-ROMs.
multiplatform
Usable by several types of computers or operating systems.
multiple instruction / multiple data
(MIMD). A kind of parallel processor in which many operations are performed on different data.
multiple perspective software developmen
An approach to software development which requires communication and collaboration between experts in a number of different fields.
Multiple Virtual Storage
(MVS). The most commonly-used operating system used on IBM mainframes; other operating systems are VM and DOS/VSE.
multiplex
(Short for "multiple access"). 1. A type of signal made of two or more signals are combined into a single signal to transmit over a communications channel. 2. To send two or more signals at the same time over a single communication channel.
Multiplexed Information and Computing Se
(Multics). An early (1969) timesharing operating system, developed by MIT, GE, and Bell Laboratories, and introducing many new operating system features.
multiplexer
(MUX). A hardware device that enables two or more signals to be transmitted over the same circuit by temporarily combining them into a single signal. On the receiving end, the signals are divided again by a demultiplexer.
multiplexing
A way of combining two or more signals into a single signal for transmission via a telephone wire, television broadcast, microwave, or another medium. At the receiving end, the signals are separated again by a demultiplexer. Different multiplexing technologies are time division multiplexing (TDM), frequency division multiplexing (FDM), and code division multiple access (CDMA).
multiport repeater
A central device to which several other devices connect, and which forwards signals and amplifies or refreshes the stream of data, which otherwise would deteriorate over a long distance.
multiprocessing
Using two or more processors in the same computer, or two or more computers connected together, to execute more than one program or instruction at the same time.
multiprocessing system
(MPS). A computer system that can run more than one program or set of instructions at a time, using two or more processors in the same computer, or two or more computers connected together.
multiprocessor
The ability for a system to perform more than one task.
Multipurpose Internet Mail Extensions
(MIME). Extensions to the Internet mail format that allow it to carry multiple types of data (binary, audio, video, graphics, etc.) as attachments to email messages.
multiscan monitor
A monitor that can scan at more than one speed, making it possible to work with various kinds of equipment and video modes.
multisync monitor
A monitor that is able to synchronize to different horizontal scan rates and refresh rates, which makes it possible to display images at various resolutions. Also called a multiscan monitor.
multitasking
Running more than one program at a time. When a machine has this capability, it is easy to switch between programs without having to quit, or to copy material from a file in one program to a file in another.
multithreading or multi-threading
Within a single program, processing more than one transaction at a time.
MultiTimer Pro
A Mac program that keeps track of your time as you work on a project. It can be set to start when the user starts a specific application. It stores a full record of timed sessions in a log window, which can be programmed with a per-hour rate so you know immediately how much money you have earned.
MUSE
Multiuser Shared Environment. A variation of MUD, also called multiuser simulation environment.
MUSH
Multi-User Shared Hallucination. A type of MUD in which the players themselves can construct new rooms, or make objects and puzzles for each other.
music CD
Usually means an audio CD, but can also mean a CD-ROM that contains sound files, such as an interactive music group CD-ROM.
Music Markup Language
MusicML. An XML application for incorporating musical symbols into web pages.
musical instrument digital interface
(MIDI). A way of communicating instructions for playing music from one electronic device to another; for example, from a synthesizer to a computer to a musical instrument. MIDI includes hardware (the electronic instruments and the interface between devices) and software (the set of rules for encoding and transfer of sound information). With MIDI, a musician can use a keyboard to simulate the sounds of many different instruments, plus add special effects. A MIDI file does not store sound as a wave file does; rather, it stores information on how to create the sounds. Some of the parameters indicated by a MIDI file are pitch, loudness, timbre, and length of a note. Because MIDI instructions resemble a musical score, a MIDI file can be edited in many ways: for example, the tempo can be changed, one instrument can be changed to another, or the whole composition can be transposed to a different key. MIDI files take up less storage space than files that store actual sounds.
MusicMatch
An MP3 player, ripper and encoder. MusicMatch makes it possible to play MP3s, download an MP3 to a file, and create original MP3s.
MusicML
Music Markup Language. An XML application for displaying musical notation in Web pages as easily as text. MusicML is free for non-commercial use.
MuTeX
An extension of TeX that can be used for music typesetting.
MUX
(Multiplexer). A hardware device that enables two or more signals to be transmitted over the same circuit at the same time by temporarily combining them into a single signal. On the receiving end, the signals are divided again by a demultiplexer.
mv
A UNIX command which is used to rename a file.
MV
Millivolt. One thousandth of a volt.
MVC
Model View Controller. The MVC is the paradigm behind the original highly interactive OS called the Smalltalk-80. The Smalltalk-80 OS is a mixture of text and graphics and input is primarily done with a mouse. Smalltalk was originally used for the Xerox PARC, where Steve Jobs found it and reworked it as the OS for the Macintosh; from there the highly popular interface was copied by many preceding OS's (READ: Windows!).
MVS
Multiple Virtual Storage. The most commonly-used operating system used on IBM mainframes; other operating systems are VM and DOS/VSE.
MySQL
MySQL is a true multi-user, multi-threaded SQL (Structured Query Language) database server. SQL is the most popular database language in the world. MySQL is a client/server implementation that consists of a server daemon mysqld and many different client programs and libraries. The main goals of MySQL are speed, robustness and ease of use. MySQL was originally developed because we at TcX needed a SQL server that could handle very large databases an order of magnitude faster than what any database vendor could offer to us. We have now been using MySQL since 1996 in an environment with more than 40 databases containing 10,000 tables, of which more than 500 have more than 7 million rows. This is about 50G of mission-critical data. The base upon which MySQL is built is a set of routines that have been used in a highly demanding production environment for many years. While MySQL is still in development, it already offers a rich and highly useful function set. The official way to pronounce MySQL is “My Ess Que Ell” (Not MY-SEQUEL).
N
An indefinite number; or, a variable that is assigned a value depending on the context.
NACK
See NAK.
NADF
North American Directory Forum. A group of organizations that offer public Directory Services in North America, according to the CCITT X.500 recommendations.
nag screen
A screen displayed in a shareware program that reminds the user to register and pay the fee. It usually appears when the program is opened or closed.
nagware
Shareware that displays a screen when the program is opened or closed that reminds the user to register and pay the fee.
NAK
Negative acknowledgement, or not acknowledged (ASCII character 21). The opposite of the ACK signal. It indicates a message was not received correctly, or that the terminal is not ready to send.
NAM
(Number Assignment Module). The component of a wireless phone that holds its telephone number and electronic serial number in memory.
name daemon
NameD or named. A UNIX process that converts hostnames to Internet addresses for TCP/IP.
name resolution
The process of mapping a name to its corresponding address. See DNS.
Name Server
A program or computer that translates one type of name into another. For example, a name server receives a query about a domain name and then sends back the IP address for that domain.
NameD
Name Daemon. A UNIX process that converts hostnames to Internet addresses for TCP/IP.
NAND
Not AND. A Boolean operation which is true unless both of its inputs are true. Another way of stating it: A Boolean operation which is true if any one of its inputs is false. A NAND B = NOT (A AND B) = (NOT A) OR (NOT B). This operation is used in logic gates within the computer.
NAND gate
A logic gate equivalent to an AND gate followed by a NOT gate. If both of its inputs are 1, its output is 0; otherwise its output is 1. NAND gates are important because all Boolean logic operations can be built out of them.
nano-
One billionth or 10^-9.
nanobot
A hypothetic, future technology robot that is microscopic in size; one possible way of using nanotechnology.
nanocomputer
A proposed future computer in which some of the logic elements are single molecules.
nanometer
One billionth of a meter. The wavelengths of light are measured in nanometers.
nanosecond
(ns). One billionth of a second (10^-9). The speed at which a computer performs logical operations is measured in nanoseconds.
nanotechnology
A hypothetical technology of the future in which objects can be designed and built on the atomic or molecular level.
NAP
Network Access Point. An interchange point for Internet traffic. A NAP acts as a backbone for the Internet. allowing ISPs to exchange data. As information travels from one network to another, it will likely pass though a NAP. A NAP can also be a site of Internet congestion.
Napier, John
A Scottish mathematician (1550-1617) who invented logarithms.
Napierian logarithm
(From John Napier) Natural logarithm.
Napster
Dot-com offering MP3 downloads, filesharing and online community resources. The Recording Industry Association of America, as well as recording artist Dr. Dre and the heavy metal group Metallica, sued Napster in early 2000 for promoting unlawful trade of copyrighted music. Judges have threatened to shut Napster down, and currently the future of the site is still in the hands of the court.
narrowband
1. A restricted frequency band, usually for a single user or used for a single purpose. 2. A range of frequencies contained within a broadband. 3. A communications channel that can carry data from 50 bps to 64 Kbps.
narrowcasting
Transmitting a radio or television program to a selected audience; for example, people who have paid for cable TV service.
NASA Stress Analysis
(NASTRAN). Software that is used to solve large stress analysis problems.
NASTRAN
NASA Stress Analysis. Software that is used to solve large stress analysis problems.
nastygram
An unpleasant electronic mail message, or a letterbomb.
National Bureau of Standards
(NBS). Now called National Institute of Standards and Technology (NIST).
National Center for Supercomputing Appli
(NCSA). A research center at the University of Illinois, Champaign/Urbana, where the first version of Mosaic was created.
national characters
Characters that do not appear in English, such as accents, the umlaut, the circumflex, and various punctuation marks; or characters that vary from country to country, such as the dollar sign $, etc. Most of these characters are not included in the ASCII character set, but they are included in extended ASCII and ANSI character sets, and other formats.
National Human Genome Research Institute
This government institution was originally established in 1989 as the National Center for Human Genome Research. Its main function is to head up the research behind the governmental Genome Project. The institution can be found at http://www.nhgri.nih.gov/. See also .bsml.
national information infrastructure
(NII). The networks of the national information superhighway, as defined by the Clinton administration. President Clinton assigned a task force to study key issues of telecommunications.
National Information Standards Organizat
(NISO). A U.S. organization that sets standards for both traditional and new-technology information services.
National Institute of Standards and Tech
(NIST). A part of the U.S. Department of Commerce, formerly called the National Bureau of Standards, that defines standards for voice, data, and video transmissions, encryption, and other kinds of technology.
National Public Telecomputing Network
(NPTN). An organization based in Cleveland, Ohio, whose goal is to make computer networking services as freely available as public libraries. NPTN started the first Freenet in 1986.
National Research and Education Network
(NREN). A supercomputer network dedicated to High Performance Computing and Communications.
National Science Foundation
(NSF). A US government agency which promotes the advancement of science and funds scientific research. NSFNet is funded by NSF.
National Science Foundation Network
(NSFNet). A high-speed network funded by the National Science Foundation that formed the original backbone of the academic part of the Internet. NSFNet extends across the continental United States and outwards to Canada, Central and South America, Europe, and the Pacific Rim. Midlevel networks are attached to this backbone and university and local networks attach to those.
National Television Standards Committee
(NTSC). Or National Television Systems Committee. A committee of the Electronics Industries Association. NTSC is the standard television video signal format used in the U.S. and Japan. In Europe the formats most often used are PAL and SECAM.
native compiler
A compiler which produces machine code for the same computer it runs on, as opposed to a cross-compiler that produces machine code for a different computer.
native language
Machine code for a computer.
native mode
The normal operating mode of a computer, as opposed to emulation mode.
NATURAL
A fourth-generation language from Software AG.
natural language
The language of human beings; language which has evolved naturally rather than being constructed logically, as computer programming languages are. English, Spanish, French, Chinese, etc. are natural languages. Computer programs which are written more like natural languages are easier for humans to use.
natural language processing
(NLP). The understanding and generating of natural human language by a computer.
natural logarithm
Log to the base e. The logarithm of 10, with e as the base, is 2.30258.
natural number
A positive integer; an integer that is greater than or equal to zero.
navigate
To find one's way around on the World Wide Web by following hypertext links from document to document, and from computer to computer.
navigating
Finding one's way around on the Internet and World Wide Web.
Nbench
A benchmark program for Windows NT. Nbench tests the CPU speed: integer and floating operations/sec; L1 and L2 cache speeds: MB/sec; main memory speed: MB/sec; disk read and write speeds: MB/sec; symmetric multiprocessing systems and multi-tasking OS efficiency using up to 20 separate threads of execution.
NBS
National Bureau of Standards. Now called National Institute of Standards and Technology (NIST).
NC
Network Computer. An Internet PC from Oracle, designed for Internet use only.
NCSA
1. National Center for Supercomputing Applications. A research center at the University of Illinois, Champaign/Urbana, where the first version of Mosaic was created. 2. National Computer Security Association.
NCSA HTTPd
NCSA Hypertext Transfer Protocol daemon. A World Wide Web server from National Center for Supercomputing Applications, which is compatible with HTTP/1.0. It can support forms, server side includes, and searches.
NE
Not equal to: <> or != .
near letter quality
(NLQ). Print quality almost as good as an electric typewriter; quality similar to a cloth-ribbon typewriter. The characters are legible but not sharp. Some dot matrix printers print NLQ.
negative acknowledgement
(NAK) ASCII character 21. The opposite of the ACK signal. It indicates a message was not received correctly, or that the terminal is not ready to send.
negative-channel metal oxide semiconduct
(NMOS). A semiconductor technology that uses negatively charged base material. NMOS circuits are used with logic and memory chips.
nerd
1. A creature in a Dr. Seuss children's book, If I Ran the Zoo. 2. A socially inept or unattractive person. 3. A person who is more interested in pursuing intellectual interests than in keeping up with trends in fashion. Since the Internet revolution, “nerd” has become a less pejorative term, and “computer nerd” is even used with admiration.
NES
Nintendo Entertainment System. Nintendo is a Japanese company that produces very popular arcade-like video games that require their own dedicated game equipment.
nesting
1. In text formatting, indenting a block of text from the left margin, usually to set off a quotation or extract. 2. In computer programming, placing a loop within a loop.
net
A network; for example, a network of computers connected to each other.
Net surfer
A person who explores the Internet for fun.
Net surfing
Traveling from site to site, exploring the Internet for fun.
net.deity
Someone who is famous and influential in Usenet circles.
net.god
On Usenet, an important and powerful personality.
net.goddess
A famous female personality on Usenet.
net.legend
On Usenet, an individual who is very well-known and has made a major contribution.
net.personality
A personality who is well-known on Usenet.
Net2Phone
A technology developed by IDT Corporation which makes it possible to place domestic and international calls from a personal computer to any telephone in the world. Any Internet user with a sound-equipped PC can initiate calls from a computer and transmit them over the Internet to a central telephone switch. The switch instantly and automatically relays the call to any telephone for full duplex voice communication, saving money on long distance calling.
netaddress
A directory retrieval service for Internet addresses, that uses intelligent agents to process requests. A single query can be used to search a set of remote directory services such as whois, Finger, and MCIMail.
NetBEUI
NetBIOS Extended User Interface. A network transport protocol that adds capabilities to NetBIOS. It is used by Microsoft and IBM network operating systems such as Windows NT and LAN Manager.
NetBIOS
Network Basic Input/Output System. An applications programming interface used in conjunction with other programs to transmit messages between applications running on PCs hooked to a local area network.
NetBIOS Extended User Interface
(NetBEUI). A network transport protocol that adds capabilities to NetBIOS. It is used by Microsoft and IBM network operating systems such as Windows NT and LAN Manager.
Netcom On-line Communication Services, I
A San Jose, California company which provides Internet access and has points of presence all over the United States.
netdead
An IRC expression for someone who is off the net (usually temporarily).
Netfind
A white pages style directory on the Internet that uses a person's name and general locality to find the email address and telephone number.
NetHack
A popular dungeon game available as freeware.
netiquette
The rules of etiquette on the Internet.
netizen
A citizen of the Internet community: a worldwide, unstructured, instantaneously linked, and organically egalitarian population.
netlag
A temporary loss of contact by a server, caused by network delays.
netnews
(nn). The program on which Usenet is run; a newsreader for Usenet messages.
NetPresenz
A program from Stairways Software for turning any Mac into a Web server.
Netrek
A Star Trek type space battle simulation game played on the Internet by up to sixteen players.
Netscape Communications Corporation
Formerly Mosaic Communications Corporation. The company that provides Netscape Navigator.
Netscape Communicator
A graphical browser from Netscape Communications Corporation, widely used for navigating the World Wide Web.
A third-party program that can be installed on a computer to enhance Netscape by adding multimedia or other capabilities. Shockwave is an example.
netter
A regular user of Usenet.
NetWare
From Novell, the most widely used software for local area networks, available for DOS, Macintosh, OS/2, VAX, and UNIX. Ethernet, Token Ring, and other configurations can be used with NetWare.
NetWare certification
Certification from Novell for competence in working with NetWare, including CNA (Certified NetWare Administrator), CNE (Certified NetWare Engineer), ECNE (Enterprise CNE), and CNI (Certified NetWare Instructor).
network
A group of interconnected computers, including the hardware and software used to connect them.
network accounting
Keeping a record of network use such as number of logons, length of time logged on, etc.
network adapter
An expansion board that makes it possible to connect a PC to a network. Network adapters are needed for Ethernet and Token Ring networks, but not for online services which use a modem to make the connection. The adapters in a network are connected to each other by cable.
Network Address Translation
A method that allows a multiple number of computers within a local network to connect to the Internet though one IP address. Network Address Translation can also act as a firewall by preventing outside computers from connecting with the local network, unless it is a connection initiated from within the local network. Network Address Translation has several variations on how it operates. Overall, it works by mapping an unregistered IP address within the local network, to a registered IP address. In addition to acting as a moderater between a local network and the Internet, the Network Address Translation can also prevent database servers from being overwhelmed if innundated with requests. When queries for the database server arrive from a client, the Network Address Translation can rewrite the headers of IP packages, and fowarded to the least busy database server. The reply packets are then returned to the client and it appears the information came from one database server and only one IP address.
network administration
Management of the software and hardware of a computer network, which includes maintaining files, overseeing security, setting up the network connections, etc.
network administrator
The person who is responsible for setting up and maintaining a network. Duties of the administrator include installing software, assigning passwords, making backups, and finding a way to restore the network when it goes down.
network architecture
The design of a network, including the hardware, software, method of connection, and protocols used.
Network Basic Input/Output System
(NetBIOS). An applications programming interface used in conjunction with other programs to transmit messages between applications running on PCs hooked to a local area network.
network closet
The place where the hardware for a network, other than cables, is installed.
Network Computer
(NC). An Internet PC from Oracle, designed for Internet use only.
Network extensible Window System
(NeWS). A windows and network system from SunSoft.
Network File System
(NFS). A protocol developed by Sun Microsystems that makes it possible for a computer to access files over a network – regardless of machine, operating system, or network architecture – as if the files were on the local disk.
Network Information Center
(NIC). An organization that provides information services to the users of a network.
Network Information Service
(NIS) (originally called Yellow Pages or yp). Sun Microsystems' client-server protocol for keeping track of user and host names on a network.
Network Interface Card
(NIC). An adapter board which is plugged into a computer so it can be connected to a network.
network latency
The delay on a network that occurs while a packet is being stored and forwarded.
network meltdown
An overload on a network.
Network News Transfer Protocol
(NNTP). Internet protocol for connecting to Usenet newsgroups and post messages.
network operating system
(NOS). An operating system which makes it possible for computers to be on a network, and manages the different aspects of the network. Some examples are Novell NetWare, VINES, Windows for Workgroups, AppleTalk, DECnet, and LANtastic.
Network Operations Center
(NOC). A center that monitors a network and communicates with other networks on the Internet, to improve services and solve problems.
Network Payment Protocol
(NPP). A non-proprietary standard governing how BIPS-enabled client software interfaces with bank payment processing systems. NPP messages are in Extensible Markup Language (XML) and begin with a Bank Internet Payment System (BIPS) XML header. They also include transaction numbers, certificates, and other security information.
network server
A central computer that stores files for a network.
Network Solutions, Inc.
(NSI). A company that provides registration services for InterNIC. NSI is a subsidiary of Science Applications International Corporation (SAIC).
Network Termination
(NT). A device that connects a customer's telephone to an ISDN line.
Network Time Protocol
(NTP) A protocol that can synchronize clocks on local computers with radio or atomic clocks on the Internet.
network to network interface
(NNI). An interface between networks.
network topology
The configuration of a network; the pattern in which the computers are interconnected. Common network topologies are the star, bus, and Token ring.
neural network
(NN). A network of many simple processors that imitates a biological neural network. Neural networks have some ability to “learn” from experience, and are used in applications such as speech recognition, robotics, medical diagnosis, signal processing, and weather forecasting. Also called artificial neural network.
New
A file menu option that opens a new file.
new media
The integration of computers, computer networking, and multimedia.
New York State Educational Research Netw
(NYSERNet). An Internet access provider and regional network in New York.
newbie
A newcomer; especially applied to new users of the Internet, Usenet, or computers.
newline
A code used to move the cursor down to the next line, also called line feed or end of line. It is not always the same character, but in many cases ASCII 10 (Control+J) is used.
NeWS
Network Extensible Window System. A windows and network system from SunSoft.
news
Top-level newsgroup category for a newsgroup with discussions related to network news.
news posting
An electronic mail message sent to a newsgroup.
news server
A computer that controls access to a newsgroup. A users must make a connection with the news server in order to post or read messages from the newsgroup.
newsfeed
A news source from which an ISP gets a newsgroup, by transfer over the Internet or other network.
newsgroup
A discussion group on the Internet which is focused on a particular topic. Discussion takes place by posting messages for everyone to read, having online conversations, and sending email messages to individuals or the group. There are thousands of newsgroups on different subjects.
newsgroups
Discussion groups on the Internet, each of which is focused on a particular topic. Discussion takes place by posting messages for everyone to read, having online conversations, and sending email messages to individuals or the group. There are thousands of newsgroups on different subjects. Newsgroup categories include rec (recreational), sci (hard science), soc (social issues), talk (talkshow-like discussions), news, k12 (k-12 education), biz (business), comp (computers), alt (alternative discussions), misc (miscellaneous), and many more. Names of newsgroups take the form comp.ai.edu (which means computers / artificial intelligence / education), biz.jobs.offered (business / jobs / offered), alt.alien.visitors (alternative / alien / visitors) rec.arts.cinema (recreational / arts / cinema). See also Usenet.
newsletter
A regular publication focused on a particular subject, such as the news of a special interest group. It may have announcements and events listings. It may be in print or sent via electronic mail.
NewsNet, Inc.
An online service based in Bryn Mawr, Pennsylvania, with a database of newsletters.
newsreader
A program which makes it possible to read newsgroup articles. Some examples are nn, rn, GNUS, and tin.
Newton
A Personal Digital Assistant from Apple.
NewWave
A graphical user interface and object-oriented environment from Hewlett-Packard which supports compound documents, linking between documents, and intelligent agents.
NexGen
A Milpitas, California, company that makes Pentium microprocessors.
NEXOR
A worldwide company specializing in communications software.
NeXT
A company in Redwood City, California, founded by Steven Jobs, cofounder of Apple Computer. NeXT developed UNIX-based workstations and NEXTSTEP software.
NEXTSTEP
A windows system and software development environment from NeXT which can be used on NeXT, HP, Sun SPARC®, 486, and Pentium computers.
"SPARC® is a registered trademark of SPARC International, Inc. in the U.S. and other countries."
NFF
1. Notes Flat File. An interchange format for the Lotus Notes/Domino platform based on Extensible Markup Language (XML). 2. No Fault Found.
NFS
Network File System. A protocol developed by Sun Microsystems that makes it possible for a computer to access files over a network – regardless of machine, operating system, or network architecture – as if the files were on the local disk.
NFY
Notify (chat).
nibble
Half a byte (four bits). Also spelled as nybble.
NIC
1. Network Information Center. An organization that provides information services to the users of a network. 2. Network Interface Card. A network adapter.
nick
A nickname used on an IRC channel. Every user has one.
nickel cadmium battery
(NiCd). The oldest type of battery used in portable computers, which uses a nickel and cadmium plate with potassium hydroxide for the electrolyte. Nickel cadmium batteries last one or two hours before recharging. Because of a phenomenon called “memory effects”, the battery must be completely drained before recharging to get the maximum charge. Nickel cadmium batteries are also highly toxic. They have been mostly replaced in portable computers by nickel metal hydride batteries.
nickel metal hydride battery
(NiMH). A type of battery used in portable computers that lasts two or three hours and is less toxic than the older nickel cadmium batteries. It has less of a problem with memory effects, so does not have to be completely drained before recharging. The nickel metal hydride battery has nickel and metal hydride plates with potassium hydroxide as the electrolyte.
nickle
Five bits.
NickServ
A bot which regulates the use of nicks (nicknames) on IRC (Internet Relay Chat).
NII
National Information Infrastructure. The networks of the national information superhighway, as defined by the Clinton administration. President Clinton assigned a task force to study key issues of telecommunications.
NiMH
Nickel Metal Hydride (NiMH), the elements used in NiMH rechargeable batteries. Rechargeable NiMH battery packs do not contain heavy metals that might have toxic effects, they store up to 50 percent more power, and they offer longer life as the batteries do not suffer from memory effects after frequent recharging. NiMH perform better than NiCAD (nickel cadmium batteries) or other alkaline batteries.
Nintendo
A Japanese company that produces very popular arcade-like video games with their own game equipment. Nintendo now has video game consoles that can be hooked up to a modem, and created XBAND, a games network where many players can play together.
Nintendo Entertainment System
(NES). Nintendo is a Japanese company that produces very popular arcade-like video games that require their own dedicated game equipment.
NIP
Non-Impact Printer. A printer that prints without striking the paper; for example, a laser printer or an inkjet printer. Non-impact printers are quieter than impact printers, such as dot matrix or daisy wheel printers.
NIS
Network Information Service (originally called Yellow Pages or yp). Sun Microsystems' client-server protocol for keeping track of user and host names on a network.
NISO
National Information Standards Organization. A U.S. organization that sets standards for both traditional and new-technology information services.
NIST
National Institute of Standards and Technology. A part of the U.S. Department of Commerce, formerly called the National Bureau of Standards, that defines standards for voice, data, and video transmissions, encryption, and other kinds of technology.
nitinol wires
Nickel-titanium filaments that contract when electrically powered; they are used in robotics. These “muscle wires” can lift thousands of times their own weight; they were used on Sojourner, the robot that explored Mars.
NLP
1. Natural Language Processing. 2. Network Layer Protocol.
NLQ
Near Letter Quality. Print quality almost as good as an electric typewriter; quality similar to a cloth-ribbon typewriter. The characters are legible but not sharp. Some dot matrix printers print NLQ.
NMOS
Negative-channel Metal Oxide Semiconductor. A semiconductor technology that uses negatively charged base material. NMOS circuits are used with logic and memory chips.
NN
Neural Network. A network of many simple processors that imitates a biological neural network. Neural networks have some ability to “learn” from experience, and are used in applications such as speech recognition, robotics, medical diagnosis, signal processing, and weather forecasting. Also called artificial neural network.
nn
(netnews). The program on which Usenet is run; a newsreader for Usenet messages.
NNI
Network to Network Interface. An interface between networks.
NNTP
Network News Transfer Protocol. Internet protocol for connecting to Usenet newsgroups and post messages.
no-op
1. (no operation). A machine instruction that does nothing in itself, but holds a place for an instruction to be entered later. Also called do-nothing operation. 2. A person who has no effect, or an action that has no effect.
NOC
Network Operations Center. A center that monitors a network and communicates with other networks on the Internet, to improve services and solve problems.
Nodal Switching System
(NSS). The main nodes in the NSFnet backbone through which routing is done.
noise
An outside signal that interferes with a communications transmission. It can come from heavy machinery, power line spikes, nearby TVs or radios, etc.
non-impact printer
A printer that prints without striking the paper; for example, a laser printer or an inkjet printer. Non-impact printers are quieter than impact printers, such as dot matrix or daisy wheel printers.
non-interlaced display
A display technology in which every line of information is sent to the screen. The non-interlaced monitors do not flicker as the old-style interlaced displays, and so reduce eyestrain.
non-pre-emptive multitasking or non-pree
A multitasking environment in which a program running in the background can only receive processing time when the program in the foreground allows it; an application can give up control of the processor to another application only at certain points, such as when it is ready for input from the keyboard. This method of multitasking may allow one program to dominate the computer's resources so other programs have limited access to the CPU. It is also called cooperative multitasking. Contrast with pre-emptive multitasking.
non-volatile memory or nonvolatile memor
Memory that does not lose its content when the power is turned off. For example, ROM, PROM, EPROM, EEPROM.
non-volatile random access memory
(NVRAM). A kind of static random access memory which maintains its content either by having a battery continuously connected to it or by saving its contents to EEPROM before the power is turned off and reading it back in when the power is restored.
non-volatile storage or nonvolatile stor
Storage that retains its content when the power is shut off, such as floppy disks, hard disks, CD-ROM, and tapes.
nonillion
10^30 (U.S. and Canada); 10^54 (Europe).
nonlinear video
A linear video is viewed or edited in a linear sequence. CD-ROMs and LaserDiscs can display nonlinear video, in which the user can jump from frame to frame or clip to clip in any order.
nontrivial
Not easy, not simple; a word applied to programming problems.
NOR
Not OR. A Boolean function which is true if none of its inputs are true, and false if any one of its inputs is true; in other words, it is true if all inputs are false, and false if any input is true.
NOR gate
A Boolean logic gate used in computer arithmetic. The NOR gate has an output of 0 if either or both of its inputs is 1, and is equivalent to an OR gate followed by a NOT gate. An exclusive NOR has an output of 1 if both of its inputs are the same.
normal distribution
Gaussian distribution; the frequency distribution of many natural phenomena, which can be graphed as a bell-shaped curve.
North American Directory Forum
(NADF). A group of organizations that offer public Directory Services in North America, according to the CCITT X.500 recommendations.
Norton SI
Norton System Information. A Norton utility that measures CPU speed, disk speed, and overall computer performance.
Norton Utilities
A set of utilities programs from Symantec that includes file backup, file recovery, disk diagnosis and repair, optimization, and more. Norton Utilities is available for PC and Macintosh.
Norton, Peter
Developer of Norton Utilities.
NOS
Network Operating System. An operating system which makes it possible for computers to be on a network, and manages the different aspects of the network. Some examples are Novell NetWare, VINES, Windows for Workgroups, AppleTalk, DECnet, and LANtastic.
A Boolean logic gate which has an output of 1 if the input is 0, and an output of 0 if the input is 1. It is called an inverter.
notebook
A personal computer which weighs around six pounds and is approximately the size of a looseleaf notebook, a little smaller than a laptop computer.
Notes Flat File
(NFF). An interchange format for the Lotus Notes/Domino platform based on Extensible Markup Language (XML).
Nova
A minicomputer introduced in 1969 by Data General, which made some advances in computer technology at the time.
NovaNET
An educational network created by the University of Illinois, which offers lesson materials in many subject areas, from elementary school level to postgraduate work.
Novell NetWare
From Novell, the most widely used software for local area networks, available for DOS, Macintosh, OS/2, VAX, and UNIX. Ethernet, Token Ring, and other configurations can be used with NetWare.
Novell, Inc.
A software company in Provo, Utah, known mainly for Novell NetWare and other networking products.
novelty typeface
An elaborate or dramatic type, such as a script typeface or shaded type. Novelty types are not very good for regular text but are good to use for headlines and special effects.
novemdecillion
10^60 (U.S. and Canada); 10^114 (Europe).
NPP
Network Payment Protocol. A non-proprietary standard governing how BIPS-enabled client software interfaces with bank payment processing systems. NPP messages are in Extensible Markup Language (XML) and begin with a Bank Internet Payment System (BIPS) XML header. They also include transaction numbers, certificates, and other security information.
NPTN
National Public Telecomputing Network. An organization based in Cleveland, Ohio, whose goal is to make computer networking services as freely available as public libraries. NPTN started the first Freenet in 1986.
NREN
National Research and Education Network. A supercomputer network dedicated to High Performance Computing and Communications.
ns
Nanosecond. One billionth of a second (10^-9). The speed at which a computer performs logical operations is measured in nanoseconds.
NSF
National Science Foundation. A US government agency which promotes the advancement of science and funds scientific research. NSFNet is funded by NSF.
NSFNet
National Science Foundation Network. A high-speed network funded by the National Science Foundation that formed the original backbone of the academic part of the Internet. NSFNet extends across the continental United States and outwards to Canada, Central and South America, Europe, and the Pacific Rim. Midlevel networks are attached to this backbone and university and local networks attach to those.
NSI
Network Solutions, Inc. A company that provides registration services for InterNIC. NSI is a subsidiary of Science Applications International Corporation (SAIC).
NSS
Nodal Switching System. The main nodes in the NSFnet backbone through which routing is done.
NT
1. Network Termination. A device that connects a customer's telephone to an ISDN line. 2. Windows NT.
NT File System
(NTFS). The file system used by Windows NT. It supports multiple file systems, has file recovery for hard disk crashes, uses the Unicode character set, and provides for file names up to 255 characters long.
NT server
Windows NT Server. The server version of Windows NT, which supports symmetric multiprocessing and online transaction processing for a large number of users.
NTF
No Trouble Found. (IBM computer maintenance abbreviation.)
NTFS
NT (New Technology) File System. The file system used by Windows NT. It supports multiple file systems, has file recovery for hard disk crashes, uses the Unicode character set, and provides for file names up to 255 characters long.
NTiogen
The Windows NT port of the popular UNIX benchmark IOgen, written by Symbios Logic. The program displays as output the number of processes doing input/output, the average response time, the number of I/O operations per second, and the number of kilobytes per second.
NTP
Network Time Protocol. A protocol that can synchronize clocks on local computers with radio or atomic clocks on the Internet.
NTS
Windows NT Server. The server version of Windows NT, which supports symmetric multiprocessing and online transaction processing for a large number of users.
NTSC
National Television Standards Committee. Or National Television Systems Committee. A committee of the Electronics Industries Association. NTSC is the standard television video signal format used in the U.S. and Japan. In Europe the formats most often used are PAL and SECAM.
nude
A term referring to computers that arrive from the factory without an operating system installed.
Nullsoft
The software company that produced the Winamp MP3 player, Shoutcast streaming software, and other freeware.
Num Lock
Number lock. A key that switches the function of the numeric keypad between numeric mode and the mode where the keys move the cursor.
number assignment module
(NAM). The component of a wireless phone that holds its telephone number and electronic serial number in memory.
number crunching
The performance by a computer of massive amounts of mathematical calculations.
number sign
ASCII character 35: # .
numeral row
The row of numeric keys on a keyboard.
numeric data
Data in the form of numbers; specifically quantities used for calculation.
numeric field
A data field for typing in numeric characters.
numeric keypad
A section of a computer keyboard, usually to the right of the typewriter keys, which looks like the keys on an adding machine or calculator. The numeric keypad can be used with the calculator desktop utility to perform mathematical operations. The numeric keypad also has arrow keys which can be used to move the cursor.
Numeris
The ISDN network of France Telecom.
NVRAM
Non-Volatile Random Access Memory. Static RAM which is preserved when the power is turned off, either by means of a battery connected to it, or by saving to EEPROM and reloading when the power is switched back on.
nybble
Half a byte (four bits). Also spelled as nibble.
NYSERNet
New York State Educational Research Network. An Internet access provider and regional network in New York.
NZ
Non Zero. A value that is not zero; greater or less than zero.
O2
Object-Oriented. An object-oriented database language.
OAB
One-to-All Broadcast.
Oberon
A procedural programming language which evolved from Modula-2.
object
In object-oriented design or programming, a data item with instructions for the operations to be performed on it.
object code
Machine code generated from source code by an assembler or compiler.
object computer
1. The computer that receives a communication, such as a fax or modem transmission. 2. The computer into which a program from a source computer is loaded and run.
object linking and embedding
(OLE). A way of connecting a file with objects from other applications. For example, a page layout file could have a spreadsheet chart, a word processing file, and a graphics file included. An embedded object becomes part of the document in which it is embedded, and is no longer linked to the source document. A linked object is displayed in the destination document but remains in the source document; when a change is made in a linked object, all files connected with it are automatically updated.
object linking and embedding custom cont
(OCX). A special-purpose program module that can be used by applications in a Windows environment. Examples of functions handled by OCX are scroll bars and the ability to resize windows. OCX controls superseded VBX controls, which were written in Visual Basic. OCX controls have been superseded by ActiveX controls; however, ActiveX is backward compatible with OCX. OCX control files end with the .OCX extension.
Object Lisp
An object-oriented version of the Lisp programming language.
Object Management Group
(OMG). An international consortium that sets standards for object-oriented programming.
object management system
In an Integrated Project Support Environment, the system that maintains information about the software being developed.
object program
A program that has been translated from the source language in which it was written into machine language, which can be executed by the computer.
Object Request Broker
(ORB). A program that controls the communication between a client and an object on a server. ORB is a standard of the Object Management Group (OMG).
object technology
(OT). Software development using objects as components with which to build applications.
object-oriented
(OO). Having to do with or making use of objects; an object in this sense is a component containing both data and instructions for the operations to be performed on that data. In object-oriented programming, these reusable components are linked together in various ways to create applications.
object-oriented database
(OODB). A database in which data is stored as objects in an object-oriented programming environment, and which is managed by an object-oriented database management system.
object-oriented graphics
Graphic images represented in the computer as instructions to draw lines or objects, rather than as bitmaps. Also called vector graphics.
object-oriented interface
A graphical user interface such as in Macintosh, Windows or Motif.
object-oriented programming
(OOP). An approach to programming in which each data item with the operations used on it is designated as an object; the routines used to operate on the data item are called methods; and objects are grouped in a hierarchy of classes, with each class inheriting characteristics from the class above it. Some uses of object-oriented programming are simulation; work with vectors and other mathematical objects; and work with graphic objects. Examples of object-oriented programming languages are SIMULA, Smalltalk, C++, Object Pascal, Objective C, Oblog, Eiffel, ESP, ACTOR, and Loops.
object-oriented programming language
A language used in object-oriented programming.
Objective C
An object-oriented C programming language released in slightly different versions by Stepstone, NeXT and GNU. It is available for MS-DOS, Macintosh, VAX/VMS and UNIX.
Objective PASCAL
An extension of PASCAL which has object-oriented programming features.
OBKB
An ackronym to be used while in real-time chat; it means “Okay, bye bye.”
oblique stroke
ASCII character 47: / .
obliqueness
In typography, the degree to which type slants, either to the right or left. Italic fonts have a built-in slant; some programs allow the user to slant type, determining the direction and degree.
OCR
Optical Character Recognition. The ability of a computer to recognize characters optically. OCR programs are used with scanners to enter text into the computer when there is already a hardcopy version. A page of text scanned with OCR does not read as a graphics file, the way other scanned images do. It can be edited and formatted just like any other text file. Text scanned with OCR will lose some of its formatting, and when a letter is indistinct, the program will guess, so typos can creep in. Some OCR programs can recognize handwritten characters.
octal
Base-8 notation. Octal numbers use only the digits 1, 2, 3, 4, 5, 6, 7; the second column to the left is the 8s place. For example, 36 octal is 6 ones and 3 eights, or 30 decimal. Octal notation can be used as a shortcut for representing six-bit binary characters by converting each three bits into one octal digit, this way: 011 010 binary = 32 octal = 26 decimal.
octet
Eight bits. Octet is sometimes used instead of the term byte to avoid confusion, because not all computer systems use bytes that are eight bits long.
octillion
10^27 (U.S. and Canada); 10^48 (Europe).
octodecillion
10^57 (U.S. and Canada); 10^108 (Europe).
octothorpe
ASCII character 35: # . Also called hash mark or number sign.
OCX
Object Linking and Embedding (OLE) Custom Control. A special-purpose program module that can be used by applications in a Windows environment. Examples of functions handled by OCX are scroll bars and the ability to resize windows. OCX controls superseded VBX controls, which were written in Visual Basic. OCX controls have been superseded by ActiveX controls; however, ActiveX is backward compatible with OCX. OCX control files end with the .OCX extension.
ODA
Open Document Architecture. An ISO standard for documents which allows for the transfer of text, graphics, and facsimiles between platforms.
ODBC
Open DataBase Connectivity. An interface that makes it possible to access different database systems with a common language. ODBC is based on CLI (Call Level Interface); there are ODBC drivers and development tools for Windows, Macintosh, UNIX, and OS/2.
odd parity
A form of error checking of transmitted data in which a parity bit is 1 when there is an odd number of 1 bits in the byte.
Ode
An object-oriented database from AT&T.
OEM
Original Equipment Manufacturer. A company that manufactures a product and sells it to a reseller. OEM can also refer to the reseller itself in the sense that resellers are “OEM customers.” As customers, they either add value to the product prior to reselling it, label it privately, or bundle it with their own products.
OEM character set
The extended ASCII character set of the IBM PC, used with DOS and some Windows fonts.
OEM font
A font that uses the OEM character set.
Oersted
The unit of magnetic intensity in the centimeter-gram-second system. Named for Hans Christian Oersted, Danish physicist (1777-1851).
off hook
(OH). A modem status signal indicated by a light on the modem, which means the local modem can send but not receive transmissions. This is equivalent to having a telephone off the hook.
off-site storage
Files stored in a separate location from the main data library; this provides an extra copy in case of fire or theft.
OfficeJet
A Hewlett-Packard inkjet printer, copier and fax machine all in one unit.
offline
Not online. Not connected to the computer and turned on (said of peripheral devices); or not connected to a computer network.
offline browser or off-line browser
A program that can be used to download email or other material from an online service, which can be read later, offline. This kind of software can save money for people who pay for by the hour for online services.
offline reader or off-line reader
A program that can be used to download email or other material from an online service, which can be read later, offline. This kind of software can save money for people who pay for by the hour for online services.
offline storage
External storage on disks and tapes.
offline world
The world that exists outside the online world of computers and networks.
offload
To remove data from a computer and put it on another computer or storage medium.
OFX
Open Financial Exchange. An open specification for online transfer of financial data, combining Microsoft's Open Financial Connectivity, Intuit's OpenExchange, and CheckFree's electronic banking and payment protocols. OFE can directly connect customers with their financial institutions, and can be used for such transactions as downloading bank and credit card statements; transferring funds; making payments; and billing. OFX is based upon SGML, and is designed to be easy to learn and extensible.
OH
Off Hook. A modem status signal indicated by a light on the modem, which means the local modem can send but not receive transmissions. This is equivalent to having the telephone off the hook.
ohm
A unit of electrical resistance; the resistance of a conductor in which a potential difference of one volt produces a current of one ampere. Named after Georg Simon Ohm, German physicist (1787-1854).
Ohm, Georg Simon
The German physicist (1787-1854) whose name is used for the unit of electrical resistance (ohm). See Ohm’s law.
Ohm's Law
A law which describes the way electricity works: I = V/R where I = current, in amperes; V = voltage, in volts; and R = resistance, in ohms.
OnLine Analytical Processing. A method of database indexing that enhances quick access to data, especially in queries calling for large quantities of data or viewing the data from many different aspects.
OLE
Object Linking and Embedding. A way of connecting a file with objects from other applications. For example, a page layout file could have a spreadsheet chart, a word processing file, and a graphics file included. An embedded object becomes part of the document in which it is embedded, and is no longer linked to the source document. A linked object is displayed in the destination document but remains in the source document; when a change is made in a linked object, all files connected with it are automatically updated.
OLE custom control
(OCX). A special-purpose program module that can be used by applications in a Windows environment. Examples of functions handled by OCX are scroll bars and the ability to resize windows. OCX controls superseded VBX controls, which were written in Visual Basic. OCX controls have been superseded by ActiveX controls; however, ActiveX is backward compatible with OCX. OCX control files end with the .OCX extension.
Olivetti
An Italian company which produces computers, office machines, and printers.
OLTP
On-Line Transaction Processing. Real-time processing of transactions on the computer.
OMF
Weather Observation Markup Format. An application of XML used to encode weather observation reports, forecasts, and advisories.
OMG
Object Management Group. An international consortium that sets standards for object-oriented programming.
Optical character recognition software from Caere Corporation, Los Gatos, California, available for PC and Macintosh.
OMR
Optical Mark Reader. A scanning device that can read marks such as pencil marks on a page; used to read forms and multiple-choice questionnaires.
on hook
Not off hook; said of a telephone line available to receive incoming calls.
on-line
Information which does not need a modem to be accessed. See also on-line help, contrast with online
on-line help
Help available on the computer; for example, explanations about features of an application which is available within the application; or support accessible via network.
on-line transaction processing
(OLTP). Real-time processing of transactions on the computer.
on-site service
Service where the computer is installed, instead of having to bring the computer into a shop or ship the computer back to the manufacturer for repairs.
on-the-fly printer
A kind of impact printer that prints in a way that the type slugs do not stop moving during the time it is making an impression.
one time programmable read only memory
(OTPROM). A kind of PROM that can only be programmed once.
one-off
One at a time; for example, a CD-ROM recorder can only write one CD-ROM at a time.
online
1. Connected to the Internet or other online service that demands the use of a modem by the user; or, referring to a user who has an account which gives access to the Internet or other online service . 2. Connected to the computer (said of peripherals) 3. Connected to a computer network. Contrast with on-line.
OnLine Analytical Processing
(OLAP). A method of database indexing that enhances quick access to data, especially in queries calling for large quantities of data or viewing the data from many different aspects.
online service
A computer network accessed by modem. Online services generally charge a monthly fee, and offer such services as e-mail, information services, online shopping, news, games. Some examples are Delphi, Prodigy, America Online, MCI Mail, and CompuServe.
Ontology Markup Language
(OML). An evolution of Simple HTML Ontology Extensions (SHOE) to Extensible Markup Language (XML).
OO
Object oriented or object-oriented. Having to do with or making use of objects; an object in this sense is a component containing both data and instructions for the operations to be performed on that data. In object-oriented programming, these reusable components are linked together in various ways to create applications.
OOC
Out Of Character. A term used in online role-playing games. A player can go out of character in order to ask questions about the game, talk to game administrators, and so forth. The game is played while IC (In Character), that is, assuming the role of the character in the game.
OODB
Object-Oriented Data Base. A database in which data is stored as objects in an object-oriented programming environment, and which is managed by an object-oriented database management system.
OOGL
Object-Oriented Graphics Language.
OOP
Object-Oriented Programming. An approach to programming in which each data item with the operations used on it is designated as an object; the routines used to operate on the data item are called methods; and objects are grouped in a hierarchy of classes, with each class inheriting characteristics from the class above it. Some uses of object-oriented programming are simulation; work with vectors and other mathematical objects; and work with graphic objects. Examples of object-oriented programming languages are SIMULA, Smalltalk, C++, Object Pascal, Objective C, Oblog, Eiffel, ESP, ACTOR, and Loops.
Open DataBase Connectivity
(ODBC). An interface that makes it possible to access different database systems with a common language. ODBC is based on CLI (Call Level Interface); there are ODBC drivers and development tools for Windows, Macintosh, UNIX, and OS/2.
Open Document Architecture
(ODA). An ISO standard for documents which allows for the transfer of text, graphics, and facsimiles between platforms.
Open Financial Exchange
(OFX). An open specification for online transfer of financial data, combining Microsoft’s Open Financial Connectivity, Intuit’s OpenExchange, and CheckFree’s electronic banking and payment protocols. OFE can directly connect customers with their financial institutions, and can be used for such transactions as downloading bank and credit card statements; transferring funds; making payments; and billing. OFX is based upon SGML, and is designed to be easy to learn and extensible.
Open Look
A graphical user interface for UNIX from Sun and AT&T.
Open Shortest Path First
(OSPF). An interior gateway protocol that routes messages according to the least expensive path, developed to replace the RIP protocol.
Open Software Description format
(OSD format). A vocabulary based on Extensible Markup Language (XML), used for describing software packages and how they interrelate.
Open source Initiative
This non-profit corporation is found at opensource.org, and exists to promote the open source software format as a better alternative than existing software development methods.
Open Systems Interconnection
(OSI; also called Open Systems Interconnect). A model developed by ISO (International Organization for Standardization) to allow computer systems made by different vendors to communicate with each other. The goal of OSI is to create a worldwide open systems networking environment where all systems can interconnect. Most communications protocols today are based on the OSI model. OSI defines a framework for communications which has seven layers: 1-the physical layer, 2-the data link layer, 3-the network layer, 4-the transport layer, 5-the session layer, 6-the presentation layer, 7-the application layer. Control is passed from one layer to the next. A communication begins with the application layer on one end (for example, a user opening an application and typing a request). The communication is passed through each of the seven layers down to the physical layer (which is the actual transmission of bits). On the receiving end, control passes back up the hierarchy. See physical layer, data link layer, network layer, transport layer, session layer, presentation layer, application layer.
open-source software
(OSS). Software in which the program source code is openly shared with developers and users. Benefits of OSS are that developers can customize programs, and these innovations, in turn, are shared within the programming community so that everyone learns from each other. OSS is a concept that embraces many hardware platforms and software languages; Linux is one popular example. Two Web sites (www.opensource.org and www.mozilla.org) aim to bring together professional and amateur developers from around the world, in the hope that new technology will blossom in an OSS environment.
OpenMLS
(Open Multiple Listing Service). Software based on the XML standard, designed to improve real estate listing services on the World Wide Web.
operand
An entity on which an operation is performed, or a reference to data to be operated on.
operating system
(OS). The main control program of a computer that schedules tasks, manages storage, and handles communication with peripherals. Its main part, called the kernel, is always present. The operating system presents a basic user interface when no applications are open, and all applications must communicate with the operating system.
operating systems
(OS). An operating system is the main control program of a computer that schedules tasks, manages storage, and handles communication with peripherals. An operating system presents a basic user interface when no applications are open, and all applications must communicate with the operating system. Some computers can switch between operating systems (see dual boot) or run another operating system under emulation. Examples of operating systems are Windows, DOS, MacOS, Linux, UNIX, OS/2, RISC OS, etc.
opt-in mailing list
A mailing list that adds members only upon request.
opt-out mailing list
A mailing list that adds members without their request, but gives each member the option to request that his or her name be removed. The main problem with remove requests is that most of them are not honored, but are simply used to confirm that the email address is valid. The list will in this case continue to send mail to the user and may sign the user up for still more mailing lists.
optical character recognition
(OCR). The ability of a computer to recognize characters optically. OCR programs are used with scanners to enter text into the computer when there is already a hardcopy version. A page of text scanned with OCR does not read as a graphics file, the way other scanned images do. It can be edited and formatted just like any other text file. Text scanned with OCR will lose some of its formatting, and when a letter is indistinct, the program will guess, so typos can creep in. Some OCR programs can recognize handwritten characters.
optical chip
Integrated optical chips are a technology in development. The proposed chips would use light rather than electrical current, generate little or no heat, make faster switching possible, and be immune to electrical noise.
optical disc
A disk in which light is the medium used to record and read data. The disk is made of clear polycarbonate plastic, covered with a layer of dye, a thin layer of gold which reflects the laser beam, and a protective layer over that. A recording is made by sending pulses from a laser beam which make a pattern in the layer of dye. The recording is read later by directing a laser beam at the disk and interpreting the pattern of reflected light. CDs, CD-ROMs, and videodiscs, are commercially recorded optical disks and are not rewritable. Recordable optical disks include WORM (write once read many) disks, and CD-Rs (CD-recordables), which can be written only once; and CD-Es (CD-erasables) which can be rewritten many times.
optical fiber
The thin glass filament that makes up fiber-optic cable. Light pulses sent along the optical fibers carry digital information at high speeds.
optical mark reader
(OMR). A scanning device that can read marks such as pencil marks on a page; used to read forms and multiple-choice questionnaires.
optical memory
Memory stored in a optical medium such as a CD-ROM, and read with a laser beam.
optical mouse
A mouse that senses where it is by emitting a light which bounces off a special reflective mouse pad.
optical reader
An input device that uses light to recognize bar codes and typed or printed characters and convert them into digital codes.
optical resolution
Most often used when referring to optical scanners or digital camerals, optical resolution is the visible, or physical, resolution at which a given device captures an image. Optical resolution is measured in dots per inch (dpi). Contrast with interpolated resolution.
optical scanner
A device that uses light to read patterns, and may then convert the patterns into digital or analog signals. An optical scanner used as an input device for a computer can scan a picture or page of text and convert it into digital code as a graphics or text file on the computer. There are flatbed scanners which look like photocopiers, having a glass scanning surface to put the original on; sheetfed scanners in which the original is guided across the scanner; and handheld scanners which the user has to move across the area being scanned. See also bar code scanner, optical reader, optical character recognition.
Optical Storage Technology Association
(OSTA). An organization of optical drive manufacturers that sets standards for optical media in computing.
optimization
A series of operations that can be performed periodically to keep a computer in optimum shape. Optimization is done by running a maintenance check, scanning for viruses, and defragmenting the hard disk. Norton Utilities is one program used for optimizing.
optimize
To bring a computer into optimum shape by running a maintenance check, scanning for viruses, and defragmenting the hard disk. Norton Utilities is one program used for optimizing.
option buttons
Buttons used for selecting options in interactive forms; only one can be chosen at a time. If an option button is selected by clicking on it, all the other buttons are automatically deselected. Also called radio buttons because they work like the buttons on old-fashioned radios.
option key
A key on a Macintosh keyboard that extends the keyboard range to special characters, such as accents, copyright and trademark symbols, etc., and that is also used in some keyboard commands.
OQL
Outgoing Quality Level.
OR
A Boolean operation which is true if any one of its inputs (0, 1 or true, false) is true. An exclusive OR is true if one of the inputs is true, but not both. See also Boolean algebra, Boolean operators, AND, and NOT.
OR gate
A Boolean logic gate used in computer arithmetic. The OR gate has an output of 1 if one of its inputs is 1.
Oracle
A relational database management system for many computer platforms from Oracle Corporation, Redwood Shores, California.
Oracle 9
The Oracle 9 is produced by the Oracle corporation in CA. The Oracle 9 is a version of the relation database management system that stores data in related tables so the database is viewed in a variety of ways.
Oracle Corporation
A Redwood Shores, California software company that created the Oracle database management system and other software products for computers from PDAs to mainframes.
Oracle Rdb
A relational database for the Digital VAX series and other computers, originally Rdb from Digital Equipment Corporation, now owned by Oracle Corporation.
Orange Book
The U.S. government document presenting standards for secure computing architectures.
ORB
Object Request Broker. A program that controls the communication between a client and an object on a server. ORB is a standard of the Object Management Group (OMG).
ordinate
The y coordinate on an x,y graph (x is the abscissa).
orientation
The direction in which a page is turned for layout and printing; the two possible orientations for letter-size paper are landscape (wide) and portrait (tall).
original equipment manufacturer
(OEM). A company that manufactures a product and sells it to a reseller.
orphan
The first line of a paragraph appearing alone at the bottom of a page, with the rest of the paragraph continuing on the next page. Leaving an orphan line is considered bad style; it is better to have the first two lines of the paragraph, or move the beginning line to the next page.
OS
Operating System. The main control program of a computer that schedules tasks, manages storage, and handles communication with peripherals. Its main part, called the kernel, is always present. The operating system presents a basic user interface when no applications are open, and all applications must communicate with the operating system.
Version 3 of OS/2, named “Warp” for “warp speed,” meaning it is fast. It is a PC operating system with a graphical user interface which can run OS/2, DOS, and Windows programs.
OSD
Open Software Description format. A vocabulary based on Extensible Markup Language (XML), used for describing software packages and how they interrelate.
OSI
(Open Systems Interconnection, or Open Systems Interconnect). A model developed by ISO (International Organization for Standardization) to allow computer systems made by different vendors to communicate with each other. The goal of OSI is to create a worldwide open systems networking environment where all systems can interconnect. Most communications protocols today are based on the OSI model. OSI defines a framework for communications which has seven layers: 1-the physical layer, 2-the data link layer, 3-the network layer, 4-the transport layer, 5-the session layer, 6-the presentation layer, 7-the application layer. Control is passed from one layer to the next. A communication begins with the application layer on one end (for example, a user opening an application and typing a request). The communication is passed through each of the seven layers down to the physical layer (which is the actual transmission of bits). On the receiving end, control passes back up the hierarchy. See physical layer, data link layer, network layer, transport layer, session layer, presentation layer, application layer.
OSPF
Open Shortest Path First. An interior gateway protocol that routes messages according to the least expensive path, developed to replace the RIP protocol.
OSR2
A release of Windows 95 with some improvements that were later incorporated in Windows 98. One feature of OSR2 is support for the FAT32 file system.
OSS
Open Source Software. Software in which the program source code is openly shared with developers and users. Benefits of OSS are that developers can customize programs, and these innovations, in turn, are shared within the programming community so that everyone learns from each other. OSS is a concept that embraces many hardware platforms and software languages; Linux is one popular example. Two websites (www.opensource.org and www.mozilla.org) aim to bring together professional and amateur developers from around the world, in the hope that new technology will blossom in an OSS environment.
OSTA
Optical Storage Technology Association. An organization of optical drive manufacturers that sets standards for optical media in computing.
OT
Object Technology. Software development using objects as components with which to build applications.
OTP
The Open Trading Protocol. A worldwide standard for retail trade on the
Internet. The OTP is a set of open standards, freely available to developers and users, built on XML. The OTP standards will create a consistent framework for electronic commerce, which will be easy for consumers to use.
OTPROM
One Time Programmable Read Only Memory. A kind of PROM that can only be programmed once.
outdent
A paragraph in which the first line begins at the left margin, and the rest of the lines are indented. Also called a hanging indent.
outline font
A type font in which a character is defined by a formula describing its outline, rather than as a bitmap. An outline font can also be called a scalable font because it can be scaled to display or print at any size. Examples are TrueType and Type 1 PostScript fonts.
output
Information that comes out of the computer; for example, a picture on the screen, a printed page, sound coming from the speakers, files printed to disk or sent over a communications line.
output area
An area of memory where data is stored until it can be output; also called a buffer.
output device
A peripheral through which information from the computer is communicated to the outside world; for example, a display screen, printer, or speakers.
output devices
Peripheral devices through which information from the computer is communicated to the outside world; for example, the monitor, the printer, or speakers.
outsourcing
Paying an outside contractor to provide certain services which they may specialize in, such as software development.
OverDrive CPU
An Intel Pentium CPU which is designed to replace the older and slower 486 and Pentium CPUs by plugging into the old processor's socket or into an upgrade socket on the motherboard.
overflow
An error condition that results when a numeric value is so large that the number cannot fit in the register or field.
overrun
A condition in which data is lost because the receiving device is not able to accept data at the rate it is transmitted.
overscan
Extending beyond the normal viewing area on the monitor screen.
overstrike
To type over an already-typed character; or, a character that has been overstruck.
overwrite
To write over data that is already on a disk; for example, when updating a file.
overwrite mode
A typing mode in which the characters typed will write over any other characters already on the line; see also insert mode.
Oz-Email
An Internet access provider in Sydney, Australia.
P-mail
Regular postal service or snail mail.
P.O.D.
Piece Of Data (rather than a programming instruction).
P5
Pentium. The Intel high-performance microprocessor introduced in 1993, also called 586 or 80586. It is about twice as fast as the 486.
P6
The Pentium Pro. Successor to the Pentium microprocessor; also called 686 or 80686. The P6 has internal RISC architecture and a CISC-RISC translator. It is faster than the Pentium for 32-bit software but slower for 16-bit software.
PA-RISC
A RISC chip used in HP minicomputers and workstations.
PABX
Private Automatic Branch Exchange. A private automatic telephone exchange that allows calls within the exchange and also calls to and from the public telephone network.
pack
To store data in compressed form in such a way that the data can be restored to its original form (unpacked).
packaged software
An application program or collection of programs developed to meet the needs of a variety of users, rather than custom designed for a specific user or company. Packaged software is sold to the general public.
Packard Bell Electronics, Inc.
A leading U.S. computer vendor based in Sacramento, California. Packard Bell originally started in 1926 as a radio manufacturing company, and now markets complete computer systems in major retail chains.
packed decimal format
A means of storage in which each byte holds two decimal digits (four bits per digit), except the rightmost byte which contains one digit and the sign (+ or -). See unpacked decimal format.
packet
A unit of data formatted for transmission on a network. Data is broken up into packets for sending over a packet switching network. Each packet has a header containing its source and destination, a block of data content, and an error-checking code. All the data packets related to a message may not take the same route to get to their destination; they are reassembled once they have arrived.
packet assembler / disassembler
(PAD). A hardware device that makes it possible for a data terminal not set up for packet switching to use a packet switching network. It assembles data into packets for transmission, and disassembles the packets on arrival so they can be used.
packet cellular
Packet transmission of data via cellular network.
packet driver
Local area network software that divides data into packets for sending on the network, and reassembles the data into its original form when it arrives at its destination.
packet internet groper
(PING). A program used to test whether a particular network destination is online, by sending an Internet control message protocol (ICMP) echo request and waiting for a response. (Also called packet internet gopher).
packet overhead
On a packet-switched network, the time it takes to transmit the extra bytes of formatting information included with each packet, and to assemble and disassemble the packets. The total transmission time includes packet overhead as well as the time it takes to transmit the raw data.
packet radio
(PR). The transmission of data packets between computers by means of amateur radio. Packet radio provides electronic mail, BBS service, chat, file transfer, and games.
packet switch node
(PSN). A dedicated computer which routes packets for a packet-switched network.
packet switching
A technology for sending packets of information over a network. Data is broken up into packets for transmission. Each packet has a header containing its source and destination, a block of data content, and an error-checking code. All the data packets related to a message may not take the same route to get to their destination; they are reassembled once they have arrived. The international standard for packet switching networks is X.25.
packet-switched network
A network that in which a temporary connection is established between points for the transmission of data in the form of packets.
packets per second
(PPS). The measurement of transmission speed in a local area network.
packing density
The number of electronic components on a given area of an integrated circuit.
PackIt
A Macintosh compression format used to pack together a collection of small files before transferring them.
pad
To fill unused portions of a data structure with dummy data such as zeros, blanks, or nulls.
PAD
Packet Assembler / Disassembler . A hardware device that makes it possible for a data terminal not set up for packet switching to use a packet switching network. It assembles data into packets for transmission, and disassembles the packets on arrival so they can be used.
pad character
A dummy character which is used to fill up space or time while some operation is performed.
padding
Dummy data used to fill unused portions of a field, such as blanks or zeros.
PADtalk
A programming language used with HyperPAD.
PAGE
A computer language used for typesetting.
page
1. A piece of paper that can have text or graphics printed on it to convey information; a collection of pages is bound together to make a book, magazine, report, etc. 2. The electronic equivalent of a paper page. Word processing programs, desktop publishing programs, etc., can be divided into pages; each page on the computer will form one paper page if the file is printed. 3. In virtual memory, a block of memory that has a virtual address and can be accessed at one time. 4. In videotex, a transmitted frame. 5. To send a message to someone whose location is not definitely known, usually via a loudspeaker announcement or a beeper.
page break
1. In a document, the place where a page ends and a new page begins. A word processor will automatically insert a page break after a certain number of lines; or the user can enter a command to put a page break in a particular place. 2. A code that tells the printer where to end a page.
page description language
(PDL). A language that describes to the printer how to print a page and how to form the type and graphic elements that appear on it. Rather than download a font to the printer, the page description language gives the printer instructions for how to draw each character from outlines; graphics are produced in a similar way. Examples are Adobe PostScript and Xerox Interpress.
page header
Text that appears at the top of every page in a document, which may include page numbers, running heads, or other information.
page layout
The creation of a camera-ready page, including placement of text, pictures, and other design elements. Page layout can be done by hand, using cut and paste methods on a light table; on the computer using a page layout program; or a combination of both.
page layout program
A program used to create camera-ready copy. Examples are PageMaker, Corel Ventura Publisher, and QuarkXPress.
page makeup
The creation of a page for printing, including design elements such as type, images, headers, and footers.
page mode memory
A way of organizing memory access used commonly in DRAM chips. Ordinarily, each bit in memory is found by its row and column coordinates. Using page mode, a memory location can be found faster, because each row, or page, only needs to be selected once for all columns in that row.
page printer
A printer that prints a full page at a time; for example, a laser printer.
page recognition
The ability of software to recognize different kinds of items on a scanned page. Page recognition software can distinguish text from pictures, and converts text on the page into computer characters by means of optical character recognition (OCR).
page view
One user request to view a page. The number of times users request a page is used, for example, to determine how many times an ad is seen.
page zero
Memory locations 0 to 4095 in virtual memory.
PageMaker
A desktop publishing program from Adobe Systems, Inc., Mountain View, California. It was originally introduced by Aldus Corporation in a Macintosh version; it is now also available for PC.
pager
A small radio receiver which beeps to alert the wearer of messages or telephone calls. It displays the telephone number of the caller so the wearer can call back. Some pagers can display very short messages. Also called a beeper.
pagination
The numbering of pages. Many programs can be set up to automatically number pages when a file is printed.
paging
1. In a virtual memory computer, the transfer of pages between real storage and auxiliary storage. A page, in virtual memory, is a block of memory with its own virtual address. Paging increases the memory available to a program by temporarily transferring less-needed parts of the program's working memory from RAM into secondary storage. When a page is needed, it is read back into RAM, replacing another page which is moved into secondary storage. This juggling of memory is accomplished by a memory management unit (MMU). By using virtual memory this way, a computer can run tasks that exceed the limits of its physical memory. 2. A way of contacting a person whose exact location is not known, by means of messages, loudspeakers, and more recently by using compact electronic beepers or pagers.
pain in the net
A very annoying flamer.
paint program
A program that allows a user to “paint” on the computer screen. Using a mouse or other pointer, the user can select from various drawing and painting tools such as brushes, spray cans, etc. and a full palette of colors. The paint program uses bitmap graphics, and allow the user to control the color of each pixel. Sophisticated graphics editing capabilities such as screens, filters, etc., can be used. Painted images, which use raster graphics, are harder to scale and move around than vector graphics images. Examples of paint programs are Paint, Superpaint, Paintbrush, and Painter.
Paintbrush
A paint program for Microsoft Windows.
Painter
A paint program for Macintosh and Windows from Fractal Design Corporation, Aptos, California.
PAL
1. Phase Alternate Line (or Phase Alternation Line). The standard for color television broadcast throughout much of Europe, which has good color transmission and sends an analog signal at 625 lines of resolution 25 interlaced frames a second. France uses SECAM, and the United States uses NTSC. 2. Paradox Application Language. The programming language used with Paradox, a relational database program.
Palace, The
A multiplatform avatar-based graphical chat program.
palette
The color palette is the range of colors available to use within a program such as a paint or draw program, photo editing program, or page layout program. The tool palette is the collection of tools available to use, such as a paintbrush, charcoal, pencil, paint bucket, airbrush, etc.
PalmOS
An operating system specifically engineered for handheld devices and the small amount of memory they have available.
palmtop
A computer small enough to be carried in the palm of the hand.
pan
Short for panorama. To move one's view continuously across an area, or to move an area continuously across one's view. Passing a picture a little at a time in front of one's eyes, moving a movie or television camera across a scene, and using a computer screen to progressively display different parts of an image are all examples of panning. Panning is a mostly horizontal movement.
panic
The action taken by a program or an operating system when a serious problem makes it unable to run. It may include displaying an error message, freezing, or automatically rebooting.
PANS
Pretty Amazing New Stuff. See POTS.
Pansophic
A U.S. company specializing in software engineering.
Pantone Matching System
(PMS). A set of standard colors, with each color designated by a number. Printers use PMS sample books to pick colors and then mix the inks to the exact specifications. On the computer, many graphics programs allow the user to pick colors by PMS number and display the chosen colors (at least approximately) on the screen.
PAP
Password Authentication Protocol. A means of authenticating passwords which is defined in RFC 1334. PAP uses a two-way handshaking procedure. The validity of the password is checked at login. See also CHAP.
paper feed control character
(PFCC). A way of controlling paper feed to a line printer.
paper tape
1. A storage medium used in the early 1900s, also called punch tape. Data was stored by means of patterns of holes punched in the tape. 2. The rolls of tape used in cash registers and calculating machines.
paper-net or papernet
Regular postal service or snail mail.
paperless office
The idea of an office in which paper documents are no longer necessary. Many documents can now be stored and transferred by means of computer disks and networks, eliminating the need for hard copy. However, there are still many uses for paper.
Paradox
A relational database from Borland for IBM PC, Windows 95, and Windows NT. The Windows version has client/server capabilities.
paradox
An apparently sound argument, based on valid premises, that leads to a self-contradictory conclusion.
Paradox Application Language
(PAL). The programming language used with Paradox, a relational database program.
paragraph
From a grammatical point of view, a paragraph is one or more sentences grouped together and addressing a common subject. Word processing and hypertext markup languages treat as a paragraph any section of text that has paragraph formatting. Paragraph formatting is created by a character such as a line return at the end of the paragraph, or sometimes a character at the beginning of the paragraph.
parallel
Side by side. For example, a parallel interface can transmit eight bits (a whole byte) at one time, over eight parallel lines. A serial interface transmits only one bit at a time.
parallel computer
A computer that has more than one central processing unit; parallel computers are used for running multiple processes simultaneously.
parallel computing
Using more than one computer at the same time to solve a problem, or using a computer that has more than one processor working simultaneously (a parallel computer).
parallel interface
A port that transmits a number of bits at a time by means of multiple parallel channels. A parallel interface is used to connect the printer on a PC. A parallel interface may transmit eight bits (one byte) at a time, or several bytes at a time. A common parallel interface used in personal computers has 36 channels; eight channels are used to transfer a byte of data at one time, and the other channels are for addressing, error correction, and other control signals. A parallel interface is faster than a serial interface, but is not reliable to transmit data over long distances. Tape drives, ISA, and IDE use parallel interfaces.
parallel port
A socket on a computer for transmitting data in parallel, which means more than one bit at a time. There may be eight, 16, or 36 channels; each channel carries one bit of information, so eight channels would be used to transmit one eight-bit byte at a time. Not all the channels are used for data; some are used for control signals. A parallel port, also called a female connector, has 25 holes, and the cable that plugs into it has 25 pins. It is the kind of port used to connect tape drives, CD-ROMs, extra hard disks, and most printers. A parallel port transmits faster than a serial port, but cannot reliably send data more than 20 feet.
parallel processing
Using more than one computer at the same time to solve a problem, or using more than one processor working simultaneously within the same computer.
parallel processor
A computer that has more than one central processing unit, and can be used for parallel processing. Also called a parallel computer.
parallel transmission
The transmission of more than one bit at a time over parallel channels, as opposed to serial transmission in which one bit at a time is transmitted. A parallel cable can use eight channels to transmit one eight-bit byte at a time, or may transmit more than one byte at a time. Some of the channels may be used to transmit control signals instead of data.
param
Parameter.
parameter
In computing, a value sent to a program or operation by the user.
Parameter RAM
(PRAM). A kind of random access memory that holds basic settings for the Macintosh such as control panels and the desktop. It is refreshed by a battery when the computer is off. The PRAM can be cleared by holding down the option and command keys while booting the computer.
parameter-driven program
A program that requires the user to enter certain values (parameters) with which it then performs its operations.
paranoid security policy
A security policy which allows no access from the Internet to an organization's internal network.
PARC
Xerox Corporation's Palo Alto Research Center. The research center from which came many important innovations in the computer field, such as some elements of the graphical user interface (the mouse, windows, and icons), laser printers, object-oriented langauges, bitmap graphics, local area networks, and the personal computer itself. Most of these innovations, though discovered at PARC, were not marketed until other companies became interested in them.
parent file
In a database, the main file containing basic information about an item. One or more child files can be created with more detailed information.
parent program
The main program which is loaded into memory first, and then may load other programs (child programs).
parentheses
ASCII characters 40 and 41: ( ) , used to enclose and set off characters for various purposes in grammar, mathematics, and computer programming.
parenthesis-free notation
The same as Polish notation. A way of expressing a sequence of calculations without using parentheses to show which operation must be performed first. See Polish notation.
parity
An integer's property of being odd or even. Parity checking is used to detect errors in binary-coded data.
parity bit
When binary data (1s and 0s) is being transmitted or stored, an extra bit can be added to make the total number of 1s always odd (or always even). This extra bit is called a parity bit. If one bit of the data is transmitted incorrectly, the parity will change, making it possible to detect the error.
parity checking
An error detection technique in which an extra bit, called a parity bit, is added to each byte in a transmission, holding a 0 or 1 depending on whether the byte has an odd or even number of 1 bits. The sender and receiver agree on odd parity, even parity, or no parity. If they agree on even parity, a parity bit will be added that will make each byte even. If they agree on odd parity, a parity bit will be added that will make each byte odd. If the data is transmitted incorrectly, the change in parity will reveal the error.
parity error
A message which is displayed on the computer if an error in parity has been detected.
parse
1. To grammatically analyze a sentence or group of words, defining the parts of speech and their syntactic relationships. 2. To analyze a statement in a human or artificial language so it can be used by the computer. Parsing is used to convert natural language statements into high-level programming language, and to convert high-level programming languages into machine language.
parser
A software routine that analyzes a statement in a natural or artificial language and resolves it into a form that can be understood by the computer.
parser generator
A program which, given a formal description of a language, can generate a parser for it. An example is UNIX yacc.
partially qualified name
A qualified name that is not complete, containing some, but not all of the names in the hierarchical structure leading to the named item.
partition
A division of a disk or storage area.
Pascal
(Pa). A programming language designed by Niklaus Wirth in the early 1970s, as a simplification and modernization of ALGOL. It is named after Blaise Pascal, a French mathematician. Pascal, known for its simplicity and highly structured programming, was designed for teaching programming. Its restrictive nature makes it a safe tool for students, but can be a handicap in general-purpose programming. Nevertheless, Pascal became a widely used programming language, and was the basis for many later languages including Modula-2, Ada, dBASE, and PAL.
Pascal, Blaise
A French philosopher and mathematician (1623-1662) who developed a calculating machine in 1642.
Pascaline
Blaise Pascal's calculating machine, developed in 1642.
passive hub
A central device to which other devices connect, and which forwards signals. A passive hub can be used to connect several computers together in a star configuration; it does not regenerate signals or process them in any way.
passive matrix display
A type of liquid crystal display (LCD) which is sometimes used in portable computers. Instead of a transistor for each pixel as in active matrix display, a passive matrix display uses a series of criss-crossed wires having an LCD element at each place the wires intersect. A passive matrix display depends on its display elements to stay bright until the next refresh scan; it is not as bright as an active matrix display, but uses less power and is less expensive.
password
A secret sequence of letters and other symbols needed to log in to a
computer system as an authorized user. When a user enters a password, it appears as a line of asterisks ******* so no one can read it.
Password Authentication Protocol
(PAP). A means of authenticating passwords which is defined in RFC 1334. PAP uses a two-way handshaking procedure. The validity of the password is checked at login. See also CHAP.
password cracking
Using computer technology to discover someone else’s password, with the intent of unauthorized use.
password fishing
Attempting to con a user into revealing his or her password.
password protection
A technology that allows a system to assign login names and passwords to users. Files and directories are protected from unauthorized access by requiring users to enter a password before access is allowed.
password sniffer
A Trojan Horse program that downloads while an unsuspecting user is visiting a website, which detects the user’s password and sends it to the originator of the site.
password stealer
(PWS). A program embedded in a file to steal passwords. The user becomes vulnerable upon downloading the file. The next time the user logs on, the user's password is sent to the maker of the program, without the user's knowledge.
paste
An editing function which involves transferring text, images, or both from the clipboard into a desired location. The expression is taken from “cut and paste,” which is the way it was originally done, manually, on a layout table.
pastie
A small sticker that can be put on a keyboard key to show a special character that the key represents other than its normal character.
patch
A quick modification of a program, which is sometimes a temporary fix until the problem can be solved more thoroughly.
path
1. The exact directions to a file on a computer. These directions are usually described by means of the hierarchical filing system from the top down, stating the drive, directory, any subdirectories, the file itself, and its filename extension if it has one: c:jobscompany
esume.txt. This complete set of information is a fully qualified path. 2. The route between any two points, such as the communications channel between two computers.
pathname
The identification of a file by its name and the name of all directories leading to it. Example: zoo/animals/lions. Also called directory path.
pathname separator
A character used between the elements in a pathname. In UNIX, the / (forward slash) is used; DOS uses (backslash). Example: www. xcom.com/index/file.html
pattern recognition
A branch of artificial intelligence concerned with the identification of visual or audio patterns by computers. For the computer to recognize the patterns, the patterns must be converted into digital signals and compared with patterns already stored in memory. Some uses of this technology are in character recognition, voice recognition, handwriting recognition, and robotics.
pattern-matching character
A character that can be used to represent one or more other characters. In DOS and UNIX, ? can be used to represent any single character, and * can represent any group of characters. Therefore, “*.*” could be substituted for any file name; “*.BAK” would mean any .BAK (backup) file, etc.
PAX
Private Automatic Exchange. A private automatic telephone exchange that allows calls only within the exchange and not calls to or from the public telephone network.
payware
Software that is sold; commercial software (not freeware or shareware).
PB Cache
Pipeline Burst Cache or Pipelined Burst Cache. A type of cache using static RAM and pipeline processing. Pipeline burst cache is often used as a secondary cache in computers with high-speed processors to improve the computer's performance.
PBEM
Play By Electronic Mail. A kind of game playing in which each player's moves are sent to the other player(s) via electronic mail.
PBEM game
Play By Electronic Mail game. A kind of game, popular on Internet and BBS, in which each player's moves are sent to the other player(s) via electronic mail.
PBM
Play By Mail. A way of playing games in which each player sends moves by postal mail to the other player(s). It's now even faster to play by electronic mail (PBEM).
PBX
Private Branch Exchange. A telephone exchange used within an organization and located on the premises; an example would be the main switchboard in a hospital.
PC
Short for Personal Computer. There are many kinds of personal computers; PC usually refers to personal computers that conform to the standard of the IBM PC. There are more IBM PCs and PC clones in use worldwide than any other type of computer. The IBM PCs and PC clones are based on the Intel microprocessors and mostly are run with DOS or Windows. Some IBM PC models are the XT, AT, and the PS/2 numbered series which includes Models 25, 30, 50, 55, 60, 70, 80, and so forth. Some makers of PC clones are Compaq, HP, and Dell.
PC Bench
Ziff-Davis' standard benchmark for measuring the performance of PCs running DOS.
PC Card
(Personal Computer Card). Trademark name for a lightweight, removable module about the size of a credit card that adds features to a portable computer, developed by the Personal Computer Memory Card International Association (PCMCIA). It is also called the PCMCIA card. A PC Card may add memory, modem and networking capability, a radio transceiver, more hard drive space, or enhanced sound. It is a plug and play device which uses a 16-bit socket and a 68-pin connector. All PC Cards are the same length and width, but varying thicknesses are used for laptops, palmtops, etc., and according to amount of storage space required.
PC card
An expansion card for a PC. A printed circuit board which can be plugged into the computer's expansion slot to add a new feature; for example, a modem, a higher-quality display, or sound.
PC compatible
A personal computer which is compatible with the IBMPC.
PC EXPO
A trade show held twice a year (in New York in the summer, in Chicago in the fall), sponsored by the Blenheim Group PLC.
PC Paintbrush
A PC paint program from ZSoft Corporation, Marietta, Georgia.
PC-DOS
Personal Computer-Disk Operating System. An operating system developed by Microsoft and supplied with IBM PCs. Microsoft also developed MS-DOS, a very similar operating system, to be used with non-IBM PCs. Starting with DOS 6, MS-DOS and PC-DOS have different sets of auxiliary utility programs. MS-DOS and PC-DOS are both called DOS for short.
PCI
Peripheral Component Interconnect. A personal computer local bus designed by Intel, which runs at 33 MHz and supports Plug and Play. It provides a high-speed connection with peripherals and allows connection of seven peripheral devices. It is mostly used with Pentium computers but is processor independent and therefore able to work with other processors. It plugs into a PCI slot on the motherboard and can be used along with an ISA or EISA bus.
PCI bus
Peripheral Component Interconnect bus. A personal computer local bus designed by Intel, which runs at 33 MHz and supports Plug and Play. It provides a high-speed connection with peripherals and allows connection of seven peripheral devices. It is mostly used with Pentium computers but is processor independent and therefore able to work with other processors. It plugs into a PCI slot on the motherboard and can be used along with an ISA or EISA bus.
PCI slot
Peripheral Component Interconnect slot. A slot on the motherboard which is available to plug in a PCI bus.
PCI slots
Peripheral Component Interconnect slots. A PCI slot is a socket on the motherboard of the computer where a PCI bus can be plugged in.
PCjr
(PC junior). The first home computer from IBM, introduced in 1983.
PCL
Printer Control Language. The control language for HP LaserJet printers, also supported by many other printers and typesetting machines. PCL tells the printer how to print a page, as does a page description language.
PCM
A generic term for the decoding technology used in the creation of WAV files.
PCMCIA
(Personal Computer Memory Card International Association; also People Can't Memorize Computer Industry Acronyms). A Sunnyvale, California nonprofit trade association created to standardize the connection of peripherals to portable computers. PCMCIA developed the PC Card (often called the PCMCIA card), a lightweight, removable module about the size of a credit card that adds features to a portable computer.
PCMCIA card
(Personal Computer Memory Card International Association card). A lightweight, removable module about the size of a credit card that adds features to a portable computer. Its official name is the PC Card. A PCMCIA card may add memory, modem and networking capability, a radio transceiver, more hard drive space, or enhanced sound. It is a plug and play device which uses a 16-bit socket and a 68-pin connector. All PCMCIA cards are the same length and width, but varying thicknesses are used for laptops, palmtops, etc., and according to amount of storage space required.
PCS
(Personal Communication Services). Wireless communications services that use the 1900 MHz (1.9 GHz) band rather than the 800 MHz used for cellular, and that use digital technology for transmission and reception.
PCUG
PC User Group.
PD
Public Domain. Belonging to the public; not protected by copyright.
PDA
Personal Digital Assistant. A pocket-sized personal computer. PDAs usually can store phone numbers, appointments, and to-do lists. Some PDAs have a small keyboard, others have only a special pen that is used for input and output. A PDA can also have a wireless fax modem. Files can be created on a PDA which are later entered into a larger computer. Apple's Newton is a well-known PDA.
PDC
Personal Digital Communications. A second-generation wireless service which uses a packet-switching technology. Messages are split into packets of data for transmission, then reassembled at their destination. PDC is widely used in Japan.
Page Description Language. A language that describes to the printer how to print a page and how to form the type and graphic elements that appear on it. Rather than download a font to the printer, the page description language gives the printer instructions for how to draw each character from outlines; graphics are produced in a similar way. Examples are Adobe PostScript and Xerox Interpress.
PeaceNet
A network sponsored by the Institute for Global Communications for the purpose of improving worldwide communication and international relations. The network makes it possible for people involved in peace initiatives around the world to communicate with each other and share news about relevant events.
peer-to-peer network
A communications network in which any computer on the network can be a client and/or a server. Any computer can access files on any other computer in the network. Two examples are Artisoft's LANtastic and Microsoft's Windows for Workgroups.
Pegasus
An emailer program that has filtering and mailing list capabilities, available as freeware for PC and Macintosh.
PEM
Privacy Enhanced Mail. Electronic mail with confidentiality, authentication, and message integrity.
pen interface
A way of inputting information into a computer by writing with a special pen on a computer screen.
pen-based interface
A user interface in which the computer operator chooses commands and communicates with the computer by means of an inkless pen called a stylus, writing on an LCD panel or electronic tablet.
Pentium
An Intel high-performance microprocessor introduced in 1993, also called P5, 586, or 80586. The name Pentium refers to the fact that it is the fifth microprocessor in the 80×86 series. It is about twice as fast as the 486.
Pentium II
An Intel microprocessor that is an improvement on the design of the Pentium Pro, with 2 million transistors added to bring the total up to 7.5 million, and speeds of 233, 266, 300, and 333 MHz. In addition, the Pentium II features Dual Independent Bus (DIB) architecture; a singled edge contact (SEC) cartridge that fits into Slot 1; a 32K L1 cache; a 512K L2 cache; and support for MMX.
Pentium III
The Intel microprocessor that follows the Pentium II. The Pentium III runs at 450, 500, 533, 550, or 600 MHz and offers new multimedia capabilities, including full-screen, full-motion video and realistic graphics, and improvements in high-performance business desktop computing. Other features include 70 new instructions; P6 architecture; 133- or 100-MHz system bus; and a 512K L2 cache.
Pentium Pro
Successor to the Pentium microprocessor; also called P6, 686, or 80686. The P6 has internal RISC architecture and a CISC-RISC translator. It is faster than the Pentium for 32-bit software but slower for 16-bit software.
PeopleLink
An instant messaging program from idealab!
per seat
A way of licensing software based on the number of workstations on which it will be installed and used.
percent sign
ASCII character 37: % .
peripheral
Any piece of hardware connected to a computer; any part of the computer outside the CPU and working memory. Some examples of peripherals are keyboards, mice, monitors, printers, scanners, disk and tape drives, microphones, speakers, joysticks, plotters, and cameras.
Peripheral Component Interconnect
(PCI). A personal computer local bus designed by Intel, which runs at 33 MHz and supports Plug and Play. It provides a high-speed connection with peripherals and allows connection of seven peripheral devices. It is mostly used with Pentium computers but is processor independent and therefore able to work with other processors. It plugs into a PCI slot on the motherboard and can be used along with an ISA or EISA bus.
peripheral device
Any piece of hardware connected to a computer; any part of the computer outside the CPU and working memory. Some examples of peripheral devices are keyboards, mice, monitors, printers, scanners, disk and tape drives, microphones, speakers, joysticks, plotters, and cameras.
peripheral devices
Hardware connected to a computer; any part of the computer outside the CPU and working memory. Some examples of peripheral devices are keyboards, mice, monitors, printers, scanners, disk and tape drives, microphones, speakers, joysticks, plotters, and cameras.
peripherals
The hardware connected to a computer; the parts of the computer outside the CPU and working memory. Some examples of peripherals are keyboards, mice, monitors, printers, scanners, disk and tape drives, microphones, speakers, joysticks, plotters, and cameras.
Perl
Perl is a
general-purpose
programming language
invented in 1987 by Larry
Wall. With over one
million users worldwide, it
has become the language
of choice for World Wide
Web development, text
processing, Internet
services, mail filtering,
graphical programming,
systems administration,
and every other task
requiring portable and
easily-developed
solutions.
permanent font
1. A resident font. 2. A downloadable font that stays in the printer’s memory until the printer is turned off.
permanent virtual circuit
(PVC). A point-to-point connection that is established in advance. A PVC which is defined at the time of subscribing to a service is called a VPN (virtual private network). Contrast with switched virtual circuit.
permissive security policy
A security policy which allows access from the Internet to an organization's internal network, except for traffic which is specifically prohibited. Access is controlled by packet filtering gateways.
persistence
The quality or state of continuing for a long time. In computing, persistence can refer to the length of time a phosphor dot on a display screen remains illuminated after being energized by an electron beam. Persistence also refers to the quality of objects and data which remain in memory from session to session.
persistent
Existing for a long time or continuously; having persistence.
Personal Communication Services
(PCS). Wireless communications services that use the 1900 MHz (1.9 GHz) band rather than the 800 MHz used for cellular, and that use digital technology for transmission and reception.
(PCMCIA). A Sunnyvale, California nonprofit trade association created to standardize the connection of peripherals to portable computers. PCMCIA developed the PC Card (often called the PCMCIA card), a lightweight, removable module about the size of a credit card that adds features to a portable computer.
personal digital assistant
(PDA). A pocket-sized personal computer. PDAs usually can store phone numbers, appointments, and to-do lists. Some PDAs have a small keyboard, others have only a special pen that is used for input and output. A PDA can also have a wireless fax modem. Files can be created on a PDA which are later entered into a larger computer. Apple's Newton is a well-known PDA.
Persuasion
A program from Aldus which is used to create presentation graphics.
peta-
Quadrillion; 10^15. Or, in binary, 2^50 = 1,125,899,906,842,624.
petabyte
A quadrillion bytes (10^15 bytes or 2^50 bytes).
PFCC
Paper Feed Control Character. A way of controlling paper feed to a line printer.
PgDn
Page Down. This keyboard key is used to view the page below the current page showing in a screen or window.
PGM
Pragmatic General Multicast. One of two common transport protocols for general multicasting.
PGML
Precision Graphics Markup Language. A two-dimensional, scalable graphics language for increasing the ease and precision with which graphic images can be produced and integrated into documents. PGML is an application of XML, and PGML graphics can be modified with style sheets along with the XML documents that contain them.
PGP
Pretty Good Privacy. An encryption program based on RSA (Rivest-Shamir-Adleman) public-key cryptography. PGP allows users to exchange files and messages, with both privacy and authentication, over all kinds of networks. The messages are unreadable unless the receiver has an encryption key. PGP encrypts data using the IDEA (International Data Encryption Algorithm) with a randomly generated key, then encrypts the key using the receiver's public key. After the message is transmitted, PGP uses the receiver's private RSA key to decrypt the IDEA key, then decrypts the message using that key. PGP features keys longer than 128 bits, and can be used with UNIX, DOS, Windows, and Mac. Because PGP is based on public-key cryptography, no secure channels are needed to exchange keys between users. PGP can also provide digital signatures for files or messages. Free versions of PGP can be downloaded from various BBS and Internet sources. Commercial versions are available from Viacrypt.
PGPfone
A technology that uses a computer with a sound card/microphone, a modem, and PGP to encrypt telephone conversations. The voice messages are digitized, encrypted using PGP, transmitted, then decrypted and played by means of the sound card.
PgUp
Page Up. This keyboard key is used to view the page above the current page showing in a screen or window.
PH
A tool for finding people online. The Macintosh Eudora equivalent of UNIX Finger.
phase alternate line
(PAL). The standard for color television broadcast throughout much of Europe, which sends an analog signal at 625 lines of resolution 25 interlaced frames a second, giving accurate color transmission. France uses SECAM, and the U.S. uses NTSC.
PHIGS
Programmers Hierarchical Interactive Graphics System. An ANSI and ISO standard for a device-independent application programming interface used with two- and three-dimensional graphics applications in high-performance workstations.
phone tag
Two senders trying to reach other by telephone but always reaching each other's voice mail and leaving messages instead.
Photo CD
An imaging system from Kodak for storing 35mm slides or negatives on a CD-ROM. It can store 100 photographs. A drive that conforms to the CD-ROM XA standard is needed to read the files. A Kodak Photo CD player can be used to view Photo CDs on a TV screen. The Power CD from Apple also includes this capability (see Power CD).
Photo CD Catalog
A Photo CD format which can hold thousands of pictures.
Photo CD Medical
A Photo CD that can store film-based images.
Photo CD player
A CD player from Kodak that can show Photo CDs on a TV screen, and can also play audio CDs.
Photo CD Portfolio
A Photo CD format which holds up to 800 television-quality images.
photonic integrated circuit
Photonic integrated circuits are a technology in development. The proposed chips would use light rather than electrical current, generate little or no heat, make faster switching possible, and be immune to electrical noise.
Photoshop
An image editing program from Adobe Systems, Inc., Mountain View, California, available for Macintosh and Windows.
Photostyler
A graphics program for Windows.
phototypesetter
A machine that produces high-quality typeset copy for printing. The type is input by means of a keyboard and output on photographic paper or film. Phototypesetters preceded desktop publishing and laser printers. A further evolution is the imagesetter, which can produce high-quality graphics as well as type.
phreaking
Hacking into telecommunications systems, often in order to make free telephone calls.
phtml
(Pre-HTML). Some HTML documents have embedded equations or other material not expressible in HTML. To embed the non-HTML data, preprocessing instructions (PPIs) are used. Using a program called phtml, the document is then translated into a new HTML document with the equations included as inline pictures. These HTML documents with PPIs have the file extension .PHTML.
physical layer
Layer 1 of the Open Systems Interconnection (OSI) networking model, which concerns the mechanical, electrical and functional aspects of connections in a communications medium.
PIC microcontrollers were designed by Microchip and have been around for over 20 years. They were the first RISC (Reduced Instruction Set Computers) microcontrollers. For their small size and low power consumption, PIC micrcontrollers are gaining in popular among desingers and hobbyists. They are the found inside BASIC Stamp computers.
pica
1. A typewriter type that prints 10 characters per inch. Fixed-pitch computer printers usually print 10 cpi. 2. In typesetting, a pica is a measurement of space which is the same as 12 points, originally a little less than 1/6 inch. In computer page layout, pica measurement is usually represented as exactly 6 picas per inch.
picklist
A dialog box that has a scrollable list of choices from which the user can pick.
pico-
(Pronounced pee-ko.) The SI prefix meaning one trillionth or 10^-12.
picoJava
An inexpensive RISC processor which executes Java instructions without the need for an interpreter or compiler. Because picoJava executes the Java Virtual Machine instructions directly, Java applications designed for use with picoJava can be 1/3 as large but run many times faster than with a standard processor. The greatly reduced memory requirements make this chip good for hand-held PCs, cellular telephones, pagers, and network computers.
picosecond
One trillionth of a second; one thousandth of a nanosecond.
PicTeX
A version of TeX used for pictures.
Picture Level Benchmark
(PLB). A benchmark for measuring graphics performance.
picture quality scale
(PQS). A way of measuring the quality of an image by how well it is perceived by the human eye, instead of measuring differences in pixels as perceived by the computer.
pidgen+
A language used with the Apple II.
piggyback board
A small circuit board that plugs into a larger circuit board to add to its capabilities.
PING
Packet Internet Groper. A program used to test whether a particular network destination is online, by sending an Internet control message protocol (ICMP) echo request and waiting for a response. (Also called packet internet gopher).
PIO
Programmed Input/Output. Data transfer between two devices in which the data path goes through the computer's main processor. The speed of data transfer corresponds with the PIO mode: PIO mode 0 has a speed of 3.3 MBps; mode 1 is 5.2 MBps; mode 2 is 8.3 MBps; mode 3 is 11.1 MBps; mode 4 is 16.6 MBps.
pipe
1. The method by which you are connected to the internet. A “fat pipe” is a line with T1 or higher capacity. 28.8 modem users may complain: “I need a bigger pipe.” 2. A designated amount of memory used by one process to pass information along to another; that is to say, a “pipe” connects two processes so one's output can be used as the other's input.
pipeline burst cache or pipelined burst
(PB Cache). A type of cache using static RAM and pipeline processing. Pipeline burst cache is often used as a secondary cache in computers with high-speed processors to improve the computer's performance.
pipeline processing
A method of processing in which a task is performed in stages; the output of one stage is input to the next. This speeds up processing by allowing several parts of different tasks to be run at the same time.
pitch
The number of characters per inch in a given typeface. In fixed-pitch type, every character has the same width; in proportional-pitch type, some characters are wider than others, and the pitch is measured as an average character width.
pixel
Short for picture element. A pixel is the smallest logical unit of visual information that can be used to build an image. Pixels are the little squares that can be seen when a graphics image is enlarged. The more pixels in an image, the better its resolution.
pixel depth
In bitmap graphics, the number of bits per pixel, which determines the number of shades of gray or variations of color that can be displayed by a computer monitor. For example, a monitor with a pixel depth of 16 bits can display 65,536 different colors; a monitor with a pixel depth of 24 bits can display 16,777,216 colors. See 4-bit color, 8-bit color, 15-bit color, 16-bit color, 24-bit color, 32-bit color.
pixel graphics
Graphic images composed of an arrangement of little squares called pixels. Also called bitmapped graphics or raster graphics.
pixel map
A 3-dimensional array of bits represented as a 2-dimensional array of pixels, in which each pixel has a depth of a certain number of bits.
pixelated or pixellated
Visible as a pattern of pixels. A bitmapped image can be made of tiny squares which are not individually distinguished by the eye. When the image is enlarged, the pattern of squares is more obvious.
pixelation or pixellation
An effect which occurs when a bitmapped image is enlarged so that the individual pixels are obvious to the eye.
pixels
A pixel is the smallest logical unit of visual information that can be used to build an image. Pixels are the little squares that can be seen when a graphics image is enlarged. (The word pixel is short for picture element.) The more pixels in an image, the better its resolution.
pixmap
A 3-dimensional array of bits represented as a 2-dimensional array of pixels, in which each pixel has a depth of a certain number of bits.
PKI
Public Key Infrastructure
PKLite
A program from PKWare that compresses only .EXE and .COM files. PKLite files decompress automatically when loaded.
PKSFX
A file compression utility from PKWare that compresses a file into a self-extracting .EXE file.
PKUNZIP
A decompression program from PKWare for the PKZIP compression utility. It was originally for PCs, but there are versions for other computers.
PKWare, Inc.
A company in Brown Deer, Wisconsin that makes the PKZIP and PKUNZIP compression utilities. PK stands for Phil Katz.
PKZIP
A file compression utility from PKWare, available as shareware. The decompression utility is PKUNZIP. PKZIP was originally for MS-DOS, but third-party versions are available for other platforms.
place
To import a file into another file.
plain old telephone service
(POTS). The standard analog telephone service with no enhancements like call waiting, etc. POTS is said to be evolving into PANS (Pretty Amazing New Stuff).
plaintext
Text which is decrypted or nonencrypted, as opposed to ciphertext. 2. A file stored as plain ASCII data.
Platform
Computers are layered machines composed of (1) a chip-level hardware level, (2) an operating system level, and (3) an application-programs level. The platform layer of the computer is the bottommost level of these levels. In layman's terms, the platform refers to the type of operating system (Windows, DOS, Unix) or computer (PIII) being used.
play by electronic mail
(PBEM). A kind of game playing in which each player's moves are sent to the other player(s) via electronic mail.
play by mail
(PBM). A way of playing games in which each player sends moves by postal mail to the other player(s). It's now even faster to play by electronic mail (PBEM).
PLB
Picture Level Benchmark. A benchmark for measuring graphics performance.
PLCC
Plastic Leadless Chip Carrier. A less expensive version of the leadless chip carrier, which is a square chip housing with flat contacts, instead of pin connectors, on each side.
(PnP). The ability of a computer to automatically detect and configure new hardware components when they are plugged in, without requiring the user to go through complicated installation procedures. With plug and play, it should be possible to immediately use a new peripheral as soon as it is plugged in. Macintosh equipment has always been plug and play; PC users have it since Windows 95. A computer must have a plug and play BIOS on the motherboard as well as the right operating system for plug and play. Expansion boards are designed specifically for plug and play, though if an older expansion board is added, the plug and play system will help the user find the correct settings for it.
plug and pray
What you do when you're hoping plug and play will work.
plug-in
An accessory program that enhances a main application. An example is the set of additional tools and effects available to Photoshop image editor in the Plug-ins folder. There are many plug-ins for Netscape Navigator such as Shockwave and Crescendo MIDI player that give the browser special capabilities, especially for multimediaWeb sites.
plug-ins
Accessory programs that enhance a main application. See plug-in.
Pluggable Authentication Modules
Primarily used by Linux servers, PAM serves as a program that simplifies and supports authentication services. When PAM is used, system administrators do not have to recompile programs when changing user authentication schemes. Instead, a system administrator can modify authentication policies as needed by editing configuration files in PAM.
plus
ASCII character 43: + . Used as a mathematical symbol.
PLV
Production-Level Video. Very high-quality video compression, used in Digital Video Interactive technology.
PM
Preventive Maintenance. Regular inspection of computer hardware to prevent problems before they happen.
PMOS
Positive-channel Metal Oxide Semiconductor. A semiconductor technology that uses positively charged base material. PMOS circuits are used in CMOS design and in calculators and watches.
PMS
Pantone Matching System. A set of standard colors, with each color designated by a number. Printers use PMS sample books to pick colors and then mix the inks to the exact specifications. On the computer, many graphics programs allow the user to pick colors by PMS number and display the chosen colors (at least approximately) on the screen.
PNG
Acronym for Portable Network Graphics (pronounced ping), a file format for bitmapped graphic images approved by the World Wide Web Consortium as a replacement for GIF files. GIF files use a patented data compression algorithm; PNG is patent- and license-free.
PnP
Plug and Play. The ability of a computer to automatically detect and configure new hardware components when they are plugged in, without requiring the user to go through complicated installation procedures. With plug and play, it should be possible to immediately use a new peripheral as soon as it is plugged in. Macintosh equipment has always been plug and play; PC users have it since Windows 95. A computer must have a plug and play BIOS on the motherboard as well as the right operating system for plug and play. Expansion boards are designed specifically for plug and play, though if an older expansion board is added, the plug and play system will help the user find the correct settings for it.
PNP
A bipolar transistor which has a layer of N-doped material between two layers of P-doped material.
POC
Point of Contact. A contact person for a domain, IP network, or other Internet entity.
pocket computer
A computer that can fit in the user's pocket. Pocket computers run on batteries, and can be plugged into a larger computer to transfer data.
POE
PowerOpen Environment. A hardware-independent standard for open systems based on the PowerPC architecture. The standard includes API and ABI specifications. Applications certified under this standard are compliant with X/Open and Spec 1170, and will run on PowerPCs under any PowerOpen-compliant operating system. X Windows, Motif, DOS, Windows, and Macintosh applications can be run in a PowerOpen Environment.
point
1. A period or decimal point symbol. 2. A unit of measurement in typesetting; there are 72 points in an inch. Points are used to measure the height of text characters, the leading, and the vertical space between design elements. 3. To use the cursor to locate a spot on the computer screen.
point of contact
(POC). A contact person for a domain, IP network, or other Internet entity.
Point of Presence
(POP or PoP). The closest site where a user can connect to an Internet server or other remote server; or, the location where a line from a long-distance telephone carrier makes a local connection. Some Internet service providers have PoPs in several different locations so more customers can reach the service with a local call.
Point of Purchase
(POP). A terminal or vending machine in a store or shopping mall where a customer can view products with their prices and select items to buy.
point of sale
(POS). The time and place in which a transaction is made. Point of sale computer systems include cash registers, optical scanners, magnetic card readers, and special terminals. Reading product tags, updating inventory, and checking credit are some of the operations performed at the point of sale.
point size
A size used to measure typefaces. In a graphical user interface, point size can be set by selecting an area of type with the cursor and selecting a size from a pull-down menu. Newspaper column type is commonly 10 point. Book text type is usually 10, 11, or 12 point.
Point to Point Protocol or Point-to-Poin
(PPP). A protocol for communication between computers using TCP/IP, over standard telephone lines, ISDN, and other high-speed connections. PPP was developed by the Internet Engineering Task Force (IETF) and is defined in RFC 1171. It can be used to connect a computer to the Internet, for services such as the World Wide Web and email. PPP is faster than SLIP and has better error correction; it can be used with both synchronous and asynchronous transmission.
point-of-sale computing
(POS computing). Using computers to record sales data at the time and place in which a transaction is made. Point of sale computer systems include cash registers, optical scanners, magnetic card readers, and sometimes a main computer which communicates with terminals. Scanners are used to read the Universal Product Code (UPC) on the tag, which records the price and type of item sold.
point-of-sale device
A device for recording sales information at the time and place a transaction occurs. See point of sale (POS).
Point-to-Point Tunneling Protocol
(PPTP). A version of PPP (Point-to-Point Protocol) that has the ability to encapsulate packets of data formatted for one network protocol in packets used by another protocol. This tunneling technique allows TCP/IP data to be transmitted over a non-TCP/IP network. PPTP can be used to join different physical networks using the Internet as an intermediary.
pointer
1. A symbol displayed on the computer screen that is moved by means of a pointing device such as a mouse, stylus, trackball, etc. The symbol may look like an arrow or other object. The pointer can be used to locate a specific point or object on the screen, to select and move objects, to select items on a menu, etc. 2. In programming, an address or an instruction to jump to another part of the data structure. 3. A hypertext link on a WWW page.
pointing device
An input device that is used to move the pointer on the computer screen. Examples are the mouse, stylus, trackball, pointing stick and touchpad.
pointing stick
A pointing device used on some notebook computers which resembles a pencil eraser, found between G, B, and H on the keyboard. It is operated with one finger to move the cursor on the screen.
Poisson distribution
A method of determining the probability of occurrence of an unlikely event within a large number of independent trials. For example, if the average number of users at any time on a network is known, Poisson distribution can be used to determine the minimum or maximum number of users in a certain time period. Named after S.D. Poisson, French mathematician.
Poisson, Simeon Denis
A French mathematician (1781-1840). He developed the statistical method called Poisson distribution.
Polish notation
A way of expressing a sequence of calculations without using parentheses to show which operation must be performed first. For example, the expression 2(4+5), which instructs the reader to add 4 + 5 and multiply by 2, would be written * 2 + 4 5 in Polish notation. To make the calculation, read from right to left until you find an operation, then perform the operation on the numbers immediately to the right of it, and continue to the next operation. So * 2 + 4 5 becomes * 2 9 and then 18. Reverse Polish notation is worked from left to right. Polish notation was invented by Jan Lukasiewicz. Many calculators and programming language interpreters translate algebraic expressions into Polish notation before performing the calculations.
poll
1. To check the devices attached to a telecommunication line one after another, to see if any terminal is ready to transmit. 2. To check devices or memory locations for operational status or occurrence of an external event.
polling ID
Polling identification. The unique character(s) identifying a communications terminal, used for polling.
polling list
The list of stations to be polled, in sequence.
polyalphabetic cipher
A cipher in which several substitutions and/or transpositions are used.
polycarbonate plastic
The material out of which CDs and CD-ROMs are made.
polygon
In computer graphics, a sequence of straight lines that enclose an area and together form a multi-sided figure that can be filled or moved around as one object.
polygons per second
(PPS). A measurement of 3D graphics performance by drawing speed.
polyline
In computer graphics, a figure composed of a sequence of connected lines.
polymorphic
Having many forms.
polymorphic virus
A virus that changes its form with each file it infects. Since they have no consistent binary pattern, such viruses are hard to identify.
PolyView
A Windows utility for viewing GIF, TIFF and JPEG files.
poor fusing
A problem that sometimes affects printers and photocopy machines in which
the toner can be easily rubbed off the printed page. It can be caused by not enough heat in the fusing system.
pop
To take something off a stack.
PoP
Point of Presence. The closest site where a user can connect to an Internet server or other remote server; or, the location where a line from a long-distance telephone carrier makes a local connection.
POP
1. Post Office Protocol. A protocol used by mail clients to download messages from a mail server on the Internet. 2. Point of Presence. The closest site where a user can connect to an Internet server or other remote server; or, the location where a line from a long-distance telephone carrier makes a local connection. 3. Point of Purchase. A terminal or vending machine in a store or shopping mall where a customer can view products with their prices and select items to buy.
pop-up menu
A menu that expands when clicked on with a mouse or other pointer. A list of options appears, and the user can select one by scrolling through the menu with the mouse button held down, and releasing the mouse button at the desired option.
POP3 host
(Post Office Protocol, version 3 host). The central repository where electronic mail is stored before the recipient downloads it; analogous to a U.S. Mail post office box where mail is stored waiting to be picked up. In an email address, the POP3 host is the part to the right of the @ symbol.
POP3 or pop3
(Post Office Protocol, Version 3). A protocol, or set of rules, by which a client machine can retrieve mail from a mail server.
port
1. A socket at the back of a computer used to plug in external devices such as a modem, mouse, scanner, or printer. 2. In a communications network, a logical channel is identified by its unique port number. 3. To translate software from one computer system to another.
port expander
A device that enables a number of lines to be connected to one port in a computer, and may offer more than one type of interface.
port replicator
A device that is used to connect peripherals to a portable computer. It has all the same ports as those on the portable computer. The peripherals, such as a monitor, printer, modem, etc., are kept plugged into the port replicator; then the portable computer can be quickly plugged into the one unit, instead of having to connect each peripheral individually.
portability
Ease of transfer from one system to another; ease of use with a variety of platforms without modification. The term usually refers to software.
portable computer
Any computer small and light enough to carry, such as a laptop, notebook, pocket computer, or palmtop.
(POSIX). A set of standards from IEEE and ISO that define how programs and operating systems interface with each other. POSIX-compliant operating systems include Windows NT and most versions of UNIX.
portable software
Software that can be used on more than one hardware platform, and easily switched from one to another.
portal
1. A gateway or entrance. 2. A gateway to the Internet, which may be a search engine or directory web page. Examples: Infoseek, Excite, Yahoo, Lycos, AOL. A web page which is a starting point for web surfing.
portals
Web pages that serve as gateways to the Internet. A user can set up a browser to open on a favorite portal page, which is a starting point for web surfing. Most portals have links to a variety of interesting sites, and some kind of search engine or Web directory. Examples of portals are Infoseek, Excite, Yahoo, Lycos, AOL.
Portico
A virtual assistant from General Magic; a hand-carried device that reads email, screens and forwards telephone calls, and handles voice mail; it is voice activated.
porting
Translating software from one platform to another.
portrait
A way of positioning a page so it is taller than it is wide, as in portrait painting; the most common way of orienting a letter-sized page for printing. A computer printer usually gives the user a choice between portrait orientation and its opposite, landscape.
ports
1. Sockets at the back of a computer where external devices such as a modem, mouse, scanner, or printer can be plugged in. 2. In a communications network, a port is a logical channel identified by its unique port number.
POS
Point Of Sale. The time and place in which a transaction is made. Point of sale computer systems include cash registers, optical scanners, magnetic card readers, and special terminals. Reading product tags, updating inventory, and checking credit are some of the operations performed at the point of sale.
positive-channel metal oxide semiconduct
(PMOS). A semiconductor technology that uses positively charged base material. PMOS circuits are used in CMOS design and in calculators and watches.
POSIX
Portable Operating System Interface for UNIX. A set of standards from IEEE and ISO that define how programs and operating systems interface with each other. POSIX-compliant operating systems include Windows NT and most versions of UNIX.
POST
Power On Self Test. A test the PC performs on its hardware, CPU, and memory when the power is switched on.
post
To send a message to a newsgroup or mailing list. Postings are read by all; messages for individuals on a mailing list or in a newsgroup can be sent by email.
Post Office Protocol
(POP or P.O.P.). A protocol used by mail clients to download messages from a mail server on the Internet.
Postal, Telegraph, and Telephone
(PTT). The government agency that oversees postal, telegraph, and telephone services in some European countries.
postcardware
Shareware for which the only payment asked is sending a postcard to the developer.
postfix notation
The same as reverse Polish notation. A way of expressing a sequence of calculations without using parentheses to show which operation must be performed first. For example, the expression 2(4+5), which instructs the reader to add 4 + 5 and multiply by 2, would be written 2 4 5 + * in postfix notation. To make the calculation, read from left to right until you find an operation, then perform the operation on the numbers immediately to the left of it, and continue to the next operation. So 2 4 5 + * becomes 2 9 * and then 18. See also Polish notation.
Postgres
An object-relational database that is superior to traditional databases, though at times compatibility with postgres is more difficult to achieve than that with traditional databases. Postgres incorporates the below, which are unique to it as an object-relational database: classes, inheritance, types, functions; and additional features include, constraints, triggers, rules, and transaction integrity.
posting
A message sent to a mailing list or newsgroup.
PostScript
A page description language from Adobe Systems, Inc. PostScript translates the text and graphic images that appear on the computer screen into instructions for the printer. PostScript must be used with a printer that can interpret it.
PostScript Level 2
An enhanced version of PostScript which has improvements in color halftone screening, color matching, and memory management, built-in image file decompression, and the ability to work with extended character sets.
PostScript printer
A printer capable of interpreting the PostScript page description language, used for high-quality graphics and type.
PostScript printer description file
(PPD file). A file that gives the PostScript driver information about a printer.
potentiometer
1. An instrument that measures voltage or potential difference by comparing it to a standard voltage. 2. A 3-terminal resistor used to control the amount of current flowing through a circuit. The volume control on a radio or television set is an example.
POTS
Plain Old Telephone Service. The standard analog telephone service with no enhancements like call waiting, etc. POTS is said to be evolving into PANS (Pretty Amazing New Stuff).
pound sign
ASCII character 35: # .
POV
Point Of View. A term used in virtual reality.
power adapter
A transformer plugged into a wall outlet that converts the AC power from the outlet into DC power for an electronic device such as a modem.
power cycle
To turn a machine's power off and then on again, in hopes of curing a problem such as a frozen or hung state.
power down
To turn off a computer following the normal procedure, closing any open applications programs before turning off the power. This is the safe way to shut down the computer, and avoids loss of data.
power hit
A sudden increase or decrease in electric power supply, which can cause the computer to crash. Surge protectors are used to avoid problems from such variations in power.
Power Macintosh
(PowerMac). A personal computer from Apple which runs the Macintosh System 7.5 operating system and can also run DOS and Windows applications.
power management
Conserving battery power by switching to a low power consumption mode when not in use. Many portable computers, certain CPUs, and some other components have this feature.
A mode in which a computer uses very little power. Many portable computer components switch to power save mode when not in use, to conserve battery life.
power surge
A sudden rise of current or voltage in an electrical circuit that can last up to several seconds. A power surge can cause damage to a computer or its files if there is no surge protector.
power up
To turn a computer on following the normal procedure.
PowerBook
A popular series of Macintosh portable computers from Apple.
PowerCD
A CD-ROM player from Apple that can be connected to a television for use with photo CDs, a stereo for use with audio CDs, or to a Macintosh computer for both photo and audio CDs, plus data CDs.
PowerMac
(Power Macintosh). A personal computer from Apple which runs the Macintosh System 7.5 operating system and can also run DOS and Windows applications.
PowerOpen Association
An organization in Cupertino, California, which defines, sets standards for, and promotes the PowerOpen Environment, a hardware-independent standard for open systems based on the PowerPC architecture.
PowerOpen Environment
(POE). A hardware-independent standard for open systems based on the PowerPC architecture. The standard includes API and ABI specifications. Applications certified under this standard are compliant with X/Open and Spec 1170, and will run on PowerPCs under any PowerOpen-compliant operating system. X Windows, Motif, DOS, Windows, and Macintosh applications can be run in a PowerOpen Environment.
Visit the PowerPoint Web page.
PowerShare
Server software from Apple for Macintosh workgroups and enterprise networks. PowerShare provides messaging and authentication services.
Powersoft Corporation
A Concord, Massachusetts, company that developed the PowerBuilder application development system. Powersoft merged with Sybase in 1995, becoming an independent subsidiary.
PowerTalk
Apple's secure messaging software that uses the AppleTalk transport protocol. PowerTalk is included in the Macintosh operating system beginning with System 7 Pro.
PPC
PowerPC. A family of high-performance RISC microprocessors developed by Apple Computer, Motorola, and IBM (the PowerPC Alliance). The PowerPC processors are designed to emulate other CPUs, so a PowerPC can run DOS and Macintosh as well as other software. These chips are have the speed of the Pentium but use less power. PowerPC architecture is based on the POWER CPU chip, used in IBM RS/6000 workstations. The 601 is a 32-bit microprocessor with a 64-bit bus. The 603 is a 32-bit microprocessor with a 64-bit bus, with low power consumption for use in portable computers. The 620 is a 64-bit microprocessor with a 64-bit bus.
PPD file
PostScript Printer Description File. A file that gives the PostScript driver information about a printer.
pph
Pages per hour. A measurement of printer speed.
ppi
Pixels per inch. A measurement used in bitmap graphics.
ppm
Pages per minute. A measurement of printer speed.
PPN
Project-Programmer Number. Same as user ID. The term comes originally from the TOPS-10 operating system, used on the DEC PDP-10 computers.
PPP
Point to Point Protocol. A protocol for communication between computers using TCP/IP, over standard telephone lines, ISDN, and other high-speed connections. PPP was developed by the Internet Engineering Task Force (IETF) and is defined in RFC 1171. It can be used to connect a computer to the Internet, for services such as the World Wide Web and email. PPP is faster than SLIP and has better error correction; it can be used with both synchronous and asynchronous transmission.
PPS
Polygons Per Second. A measurement of 3D graphics performance by drawing speed.
pps
Packets per second. The measurement of transmission speed in a local area network.
PPTP
Point-to-Point Tunneling Protocol. A version of PPP (Point-to-Point Protocol) that has the ability to encapsulate packets of data formatted for one network protocol in packets used by another protocol. This tunneling technique allows TCP/IP data to be transmitted over a non-TCP/IP network. PPTP can be used to join different physical networks using the Internet as an intermediary.
PQS
Picture Quality Scale. A way of measuring the quality of an image by how well it is perceived by the human eye, instead of measuring differences in pixels as perceived by the computer.
PR
1. Packet Radio. The transmission of data packets between computers by means of amateur radio. Packet radio provides electronic mail, BBS service, chat, file transfer, and games. 2. Proposed Recommendation. W3C’s term for a recommendation before it is officially approved.
Praetor
An advanced plug-in for Microsoft Exchange, from Computer Mail Services (CMS), that proactively blocks spam email. Praetor provides anti-spam filtering by validating all incoming email at both the SMTP (Simple Mail Transfer Protocol) and message levels, thus serving as a comprehensive messaging firewall.
Pragmatic General Multicasting
(PGM). One of two transport protocols used for general multicasting.
PRAM
Parameter RAM. A kind of random access memory that holds basic settings for the Macintosh such as control panels and the desktop. It is refreshed by a battery when the computer is off. The PRAM can be cleared by holding down the option and command keys while booting the computer.
pre-HTML
(phtml). Some HTML documents have embedded equations or other material not expressible in HTML. To embed the non-HTML data, preprocessing instructions (PPIs) are used. Using a program called phtml, the document is then translated into a new HTML document with the equations included as inline pictures. These HTML documents with PPIs have the file extension .PHTML.
Precision Graphics Markup Language
(PGML). A two-dimensional, scalable graphics language for increasing the ease and precision with which graphic images can be produced and integrated into documents. PGML is an application of XML, and PGML graphics can be modified with style sheets along with the XML documents that contain them.
preemptive multitasking
A type of multitasking where the computer or operating system can interrupt a currently running task in order to run another task, as needed. An example would be when a program is running in the foreground and a network transmission is proceeding in the background. The operating system can allot a time slice to each task depending on its priority or the amount of resources it requires. In contrast is cooperative (non-pre-emptive) multitasking, in which it is the applications that decide when to turn over the processor to each other. Mainframes use pre-emptive multitasking, as do the UNIX, OS/2, and Amiga systems.
preference settings
A set of options within a program that the user can choose; for example, in a World Wide Web browser there are options for an email signature file, color and style of text, etc.
preferences
A menu within a program that allows the user to tailor the program to individual needs. The preferences menu can be used to set up views, pagination, mouse tracking, brush styles, default fonts, dictionaries, email signatures, and many other parameters, depending on the program.
PReP
PowerPC Reference Platform. Also called Common Hardware Reference Platform (CHRP). An open system standard for PowerPCs. It allows PowerPC-based computers to run different operating systems, including MacOS, WorkplaceOS, AIX, OS/2, Solaris, Taligent, and Windows NT. It designates ports and sockets for compatibility across platforms, and can be used with various buses.
prepress
The preparation of camera-ready materials for printing. Prepress includes typesetting, page layout, and proofreading.
presentation graphics
The use of computers to create graphic presentations for business and education. Presentation programs such as Freelance Graphics from Lotus or Hollywood from IBM have tools for drawing and painting, and can make charts using data from a spreadsheet. On the computer, the images can be viewed in sequence or as a page of miniature frames, and adapted to a common color scheme. The images can be presented on video, as a slide show with an overhead projector or 35-mm slides, or as a computer screen show. Advanced programs provide special effects such as fades or animation and sound.
presentation layer
Layer 6 of the Open Systems Interconnection (OSI) networking model, which defines file and file access formats, performs file compression, establishes a common syntax between hosts, and converts data so incompatible systems can communicate with each other.
presentation program
A program used to plan, organize, and design business or educational presentations, using drawings, charts, and text. Examples are Aldus Persuasion and PowerPoint from Microsoft. The graphics created are usually displayed as slide shows or videos. See presentation graphics.
Pretty Good Privacy
(PGP). An encryption program based on RSA (Rivest-Shamir-Adleman) public-key cryptography. PGP allows users to exchange files and messages, with both privacy and authentication, over all kinds of networks. The messages are unreadable unless the receiver has an encryption key. PGP encrypts data using the IDEA (International Data Encryption Algorithm) with a randomly generated key, then encrypts the key using the receiver's public key. After the message is transmitted, PGP uses the receiver's private RSA key to decrypt the IDEA key, then decrypts the message using that key. PGP features keys longer than 128 bits, and can be used with UNIX, DOS, Windows, and Mac. Because PGP is based on public-key cryptography, no secure channels are needed to exchange keys between users. PGP can also provide digital signatures for files or messages. Free versions of PGP can be downloaded from various BBS and Internet sources. Commercial versions are available from Viacrypt.
pretzel key
The Macintosh command key, which has a pretzel-shaped logo on it.
preventive maintenance
(PM). Regular inspection of computer hardware to prevent problems before they happen.
preview
A feature in some programs (for example, word processing and drawing programs) that shows on the screen how a document will look when printed. In WYSIWYG programs the file always shows how it will look when printed, so it is unnecessary to switch to a preview mode. A word processing program, however, shows only the text that will be printed and the page breaks, and it is necessary to switch to preview mode to see the overall look of the page, with margins, page numbers, etc.
Used in database management systems as a key field that holds a unique value.
Primary Rate Interface
(PRI). A high-speed ISDN connection (1.544 megabits/second) which can provide voice, data, or video; the equivalent of a T1 line.
primary storage
The internal memory of a computer; Random Access Memory.
Prime Computer
A manufacturer of minicomputers.
prime time
The hours when a network or time-sharing system has the highest number of users logged on.
Primenet, Inc.
A major Internet service provider in Arizona.
print ball
The metal ball-shaped print head on a ball printer.
print buffer
The computer can send data to the printer faster than the printer can print. The print buffer is an area of memory in a printer that stores output from the computer until it can be printed. If the buffer gets full, the computer must wait before it can send more data. If a printer has more than one computer hooked to it, the print buffer will hold the output from one computer while it prints output it received earlier. Also called printer buffer.
print head
In a printer, the mechanism that deposits the ink onto the paper.
print merge
Merging data from one file into another file for printing; for example, printing many copies of a form letter, with a different name and address on each letter. The names and addresses are from a separate database file.
print queue
A lineup of items waiting to be printed.
print screen
A command that prints out whatever appears on the computer screen.
print server
A computer in a network that handles printing for other computers. It may control more than one printer. The other computers send their files to the print server, and the print server sends each file to be printed when a printer is ready.
printer buffer
The computer can send data to the printer faster than the printer can print. The printer buffer is an area of memory in a printer that stores output from the computer until it can be printed. If the buffer gets full, the computer must wait before it can send more data. If a printer has more than one computer hooked to it, the printer buffer will hold the output from one computer while it prints output it received earlier. Also called print buffer.
printer cable
A cable that connects a printer to a computer.
printer control language
PCL. The control language for HP LaserJet printers, also supported by many other printers and typesetting machines. PCL tells the printer how to print a page, as does a page description language.
printer driver
A software routine that describes the physical characteristics of a particular printer, and converts data for printing into a form that printer can understand.
printer engine
The mechanism within a printer that does the actual printing, not including the computer circuitry that controls it.
printer font
A font that gives the printer instructions on how to print each character, rather than a font used to display characters on the computer screen.
printer port
A port for attaching a printer to the computer.
printer queue
A list of items waiting to be output to the printer when the printer is available.
printout
A printed copy of a file; a hard copy.
Privacy Enhanced Mail
(PEM). Electronic mail with confidentiality, authentication, and message integrity.
private automatic branch exchange
(PABX ). A private automatic telephone exchange that allows calls within the exchange and also calls to and from the public telephone network.
private automatic exchange
(PAX). A private automatic telephone exchange that allows calls only within the exchange and not calls to or from the public telephone network.
private branch exchange
(PBX). A telephone exchange used within an organization and located on the premises; an example would be the main switchboard in a hospital.
private file
A file which has very restricted access, perhaps only available to the person who created it.
Private File
A drag-and-drop 128-bit encryption and compression program from Aladdin Software, available for Mac and Windows, which can be integrated into email programs. Encrypted files sent by email can be opened by a receiver who has the password.
private key cryptography
A form of cryptography in which sender and receiver have the same key or similar keys.
private key encryption
A form of cryptography in which sender and receiver have the same key or similar keys.
private management domain
(PRMD). A private, inhouse email service that uses the X.400 protocol.
PRMD
Private Management Domain. A private, inhouse email service that uses the X.400 protocol.
Pro Photo CD
A Photo CD format which can be used to store images from professional format film.
problem-oriented language
A programming language created to address a certain kind of problem; for example, SQL is for database queries, COBOL is for business applications, and FORTRAN was created for scientific problems.
process scheduling
The scheduling of tasks in a multitasking environment, which involves assigning starting and ending times to each task.
processor cache
An area of high-speed memory linked directly to the CPU. The CPU can access information in the processor cache much more quickly than information stored in main memory. Frequently-used data is stored here.
Prodigy
An online information service developed by IBM and Sears. For a monthly fee, users get Internet access, electronic mail, weather and stock market reports, airline scheduling, email, discussion groups, games, and home shopping.
production-level video
(PLV). Very high-quality video compression, used in Digital Video Interactive technology.
productivity suite
A suite of business applications that usually includes a word processing program, a spreadsheet, a database program, a communications program, and a presentation graphics program. Examples would be Claris Works or Microsoft Office.
Professional Office System
(PROFS). An IBM office software and messaging system used mostly on mainframe computers.
PROFS
Professional Office System. An IBM office software and messaging system used mostly on mainframe computers.
prog
Program. This abbreviation is mainly used by hackers for independently created programs rather than large commercial applications; it can indicate a useful program or a harmful one.
proglet
A very short computer program written for some immediate, short-term use.
program maintenance
Updating programs from time to time to keep abreast of changes in an organization's needs or its hardware and software.
programmable
Able to be programmed; able to be given instructions.
Programmable Read Only Memory
(PROM). A memory chip that can only be programmed once. Unlike ROM, which is programmed by the manufacturer, PROM is programmed by the user. See also ROM, EPROM and EEPROM.
programmed input/output
(PIO). Data transfer between two devices in which the data path goes through the computer's main processor. The speed of data transfer corresponds with the PIO mode: PIO mode 0 has a speed of 3.3 MBps; mode 1 is 5.2 MBps; mode 2 is 8.3 MBps; mode 3 is 11.1 MBps; mode 4 is 16.6 MBps.
programmer
A person who writes instructions (programs) for computers.
programmer analyst
A combination programmer and systems analyst.
Programmers Hierarchical Interactive Gra
(PHIGS). An ANSI and ISO standard for a device-independent application programming interface used with two- and three-dimensional graphics applications in high-performance workstations.
programming
Designing and writing a computer program. The programmer must decide what the program needs to do, develop the logic of how to do it, and write instructions for the computer in a programming language that the computer can translate into its own language and execute.
project-programmer number
(PPN). Same as user ID. The term comes originally from the TOPS-10 operating system, used on the DEC PDP-10 computers.
PROM
Programmable Read Only Memory. A memory chip that can only be programmed once. Unlike ROM, which is programmed by the manufacturer, PROM is programmed by the user. See also ROM, EPROM and EEPROM.
promiscuous mode
A networking mode in which a station on a network will accept all packets, no matter what their destination address is.
promiscuous security policy
A policy of allowing everyone access from the Internet to an organization's internal network.
prompt
A message from the computer that asks the operator to do something, such as enter a command, enter a password, or enter data. An example is the DOS prompt, C:.
propagate
To move through a medium; to spread.
propagation
Movement through a conductive medium.
propagation delay
The time required for a signal to travel from one point to another.
propeller head
Somebody who wears a beanie cap with a propeller on top that turns in the breeze. Whether the person literally wears such a cap or not, this term is used to describe a person as a geek.
propeller key
The Macintosh feature key, which has an icon that looks somewhat like a propeller.
proportional-pitch type
Pitch is the number of characters per inch in a given typeface. In fixed-pitch type, every character has the same width; in proportional-pitch type, some characters are wider than others, for the sake of style. For example, an M would be wider than an I. In proportional-pitch type the pitch must be measured as an average of many character widths.
Proposed Recommendation
(PR). W3C’s term for a recommendation before it is officially approved.
proprietary software
Software that is owned by an individual or a company. To use the software, one must purchase a license.
protected mode
A mode in which Windows reserves memory for itself. By switching the microprocessor to this mode, Windows can execute several programs at once, transcending the 1-megabyte limit normally enforced on the processor.
protocol
1. Often simply referred to as a protocol, a communications protocol is a set of rules or standard designed so that computers can exchange information with a minimum of errors.See also Open Systems Interconnection Model (OSI). 2. Layer 3 of the OSI networking model, which handles data routing and addressing.
protocol converter
A device used to translate between protocols.
protocol stack
A hierarchy of protocols which work together to provide the services on a communications network. The OSI seven-layer model, SNA, and TCP/IP are examples.
protocols
Sets of rules that regulate the way data is transmitted between computers. Examples are PPP, TCP, IP, RIP, POP, SNMP, SMTP, SLIP, ARP, RARP, PAP.
proxy ARP
Using one machine to respond to ARP (Address Resolution Protocol) requests for another machine. The proxy machine routs transmission packets to the proper destination.
proxy server
A server that provides access to files from other servers by retrieving them either from its local cache or from the remote server.
prudent security policy
A security policy which disallows access from the Internet to an organization's internal network, except for traffic which is specifically allowed.
PS/2 port
A port available on most PCs that can be used to plug in a mouse or keyboard. It has a socket for a 6-pin mini-DIN plug. The PS/2 port is sometimes called the mouse port.
pseudo compiler
A compiler that generates an intermediate language, called a pseudo language, which must then be compiled or interpreted before execution. The purpose of the pseudo compiler is to make it possible to use the same source language on different types of computers.
pseudo language
An in-between language which is generated from a source language, but must be further compiled or interpreted before it can be executed. The purpose of the pseudo language is to make it possible to use the same source language on different types of computers.
pseudocode
A series of statements that outline what a computer program will do, without putting in the actual programming code. The pseudocode, which can be written in natural language, is a preliminary step in designing a program, and helps the programmer think through what steps will be necessary. At the pseudocode stage, it is not necessary to know what programming language will be used. In a later step, the pseudocode will be translated into actual computer instructions.
pseudosuit
A suit wannabee, or someone posing as a suit for the purpose of making more money. See suit.
PSN
Packet Switch Node. A dedicated computer which routes packets for a packet-switched network.
PSP
Payphone Service Provider.
PSTN
(Public Switched Telephone Network). A voice and data communications service for the general public which uses switched lines.
psychedelicware
Software which makes pretty moving pictures and patterns on the computer display screen.
ptc
A translator program which converts Pascal to C.
PTN
Public Telephone Network. A voice and data communications service for the general public which uses switched or non-switched lines.
PTT
Postal, Telegraph, and Telephone. The government agency that oversees postal, telegraph, and telephone services in some European countries.
public domain
(PD). Belonging to the public; not protected by copyright.
public domain software
Software which has no copyright protection and can be used or copied by anyone free of charge. Sometimes programmers create software and donate it for the good of the general public.
public file
A file which is available to all users accessing a network or system.
public key cryptography
A form of cryptography in which each user has a public key and a private key. Messages are sent encrypted with the receiver's public key; the receiver decrypts them using the private key. Using this method, the private key never has to be revealed to anyone other than the user.
public switched telephone network
(PSTN). A voice and data communications service for the general public which uses switched lines.
public telephone network
(PTN). A voice and data communications service for the general public which uses switched or non-switched lines.
public-key encryption
A way of encrypting messages in which each user has a public key and a private key. Messages are sent encrypted with the receiver's public key; the receiver decrypts them using the private key. Using this method, the private key never has to be revealed to anyone other than the user.
pubnet
Top-level newsgroup category for public access systems newsgroups.
puck
A device used to draw on a digitizer tablet.
puff
To decompress data that has been compressed by Huffman code. See huff.
pull
The opposite of push technology; the user decides to visit a web page or to download software rather than signing up for a service that automatically brings it to the user’s desktop.
pull-down menu
A menu that expands downward when its title is selected with the mouse. A list of options appears as long as the mouse button is held down, and the user can select an option by scrolling through the menu and releasing the mouse button when the desired option is highlighted.
pulled
User-initiated rather than automatic (pushed); for example, a download of software that is initiated by the user rather than pushed by an automated distribution system.
pulse level device
A device whose input and output are in the form of voltages. Contrast bit level device.
punch card
A thin cardboard card which can be punched with hole patterns that represent data.
punch tape
A storage medium used in the early 1900s, following the use of punch cards. Data was stored by means of patterns of holes punched in the paper tape.
punched card
An early data storage method, almost obsolete, in which thin cardboard cards are punched with holes that represented binary information. Punched cards were used with mechanical looms before the invention of computers.
punched tape
Paper tape with holes punched in it to represent data, including program instructions.
punter
A program that sends a user a very large HTML file by email, causing the user's computer to stall or freeze as it waits for the large file to download.
purge
To delete both a set of data and all references to the data.
Purple
An electric rotor cipher machine, modeled after the German Enigma machine, that was used to generate codes for the Japanese during World War II. "Purple" was the American name for the machine.
Purveyor
A World Wide Web server used with Windows NT and Windows 95.
push
1. To put something onto a stack. 2. To deliver data and services to a user’s desktop by means of push technology.
push code
To write the code for a computer program.
push technology
Internet technology that allows information to be delivered or “pushed” directly to a user who subscribes to it, rather than the user having to go look for the information on an Internet site. For example, PointCast, Yahoo, and other services provide news to users who can customize their news reports, choosing from categories such as sports, world news, stock market, etc. and entering their preferences into a database. The news and other chosen services are pushed to the user's computer by means of a web browser or other client software.
pushed
Supplied by means of push technology.
put
An FTP command to copy a file from the local computer to the remote computer.
PVC
Permanent Virtual Circuit. A point-to-point connection that is established in advance. A PVC which is defined at the time of subscribing to a service is called a VPN (virtual private network). Contrast with SVC.
pwd
A UNIX command that indicates what the current working directory is on the virtual server.
PWR
Power On. A modem status signal indicated by a light on the modem, which tells the user the power is on.
PWS
(Pass Word Stealer). A program embedded in a file to steal passwords. The user becomes vulnerable upon downloading the file. The next time the user logs on, the user's password is sent to the maker of the program, without the user's knowledge.
Q
1. A very high level language, implemented in C++. 2. Quadrature.
QA
Quality Assurance. Procedures taken to ensure that a company delivers products that conform to standards.
QAM
Quadrature Amplitude Modulation. A technique of modulation in which there are sixteen possible four-bit patterns, determined by the combination of phase and amplitude.
QBASIC
The version of QuickBASIC that comes with DOS 5 and later versions. It replaces, and accepts programs written for, Microsoft's GW-BASIC.
QBE
Query By Example. A user-friendly way of querying a database that was originally developed by IBM for use with mainframes, and later adopted by many other systems. With Query By Example, an empty record is displayed and the user types in the search keys; for example, typing “New York” in the “city” field will return all records where the city is New York.
Qbench
A DOS hard disk benchmark from Quantum Corporation, which measures data access time and data transfer rate.
QDOS
1. Quick And Dirty Operating System. An early personal computer operating system rumored to be the forerunner of PC-DOS and MS-DOS. 2. An operating system designed for the Sinclair QL computer.
QEMM
Quarterdeck Expanded Memory Manager. A DOS and Windows memory manager from Quarterdeck Office Systems, Santa Monica, California; used for IBM PCs with an Intel 80386 or higher processor.
QIC drive
(Quarter Inch Cartridge drive). A drive used to back up personal computer data on quarter inch cartridges.
QIC tape
Quarter Inch Cartridge tape. A magnetic tape used for backing up data, which comes in hard cartridges. QIC tape comes in minicartridges (3.5″) and data cartridges (5.25″). There are various types of cartridges and lengths of tape, storing from 40 megabytes to 25 gigabytes of data.
QIC Wide
Quarter Inch Cartridge Wide. A quarter inch cartridge tape from Sony that is wider than 1/4 inch. It is .315″ wide and has a greater recording density, thus increasing the storage capacity.
QIC-EX
Quarter Inch Cartridge – Extended. These magnetic tape cartridges come in both .25″ and .315″ formats and contain longer tape to extend the storage capacity of the quarter inch tape drives.
QL
(Quantum Leap). A personal computer developed by Sir Clive Sinclair and first released in 1983. It is based on the Motorola 68008 microprocessor and uses an operating system called QDOS developed by Sinclair.
QMS
Quality Micro Systems. A Mobile, Alabama manufacturer of laser printers. QMS made one of the first PostScript printers.
QTW
QuickTime for Windows. Multimedia software from Apple Computer that integrates full-motion video and sound into application programs.
quad
Two bits (a quarter of a byte).
quad-speed CD-ROM drive
(4X) A CD-ROM drive that can read information four times as fast as a music CD. At least a double speed drive is needed for multimedia CD-ROMs, and quad speed is even better.
quad-speed drive
A CD-ROM drive that is four times as fast as a single-speed drive. Quad-speed drives substantially improve the quality of multimedia.
Quadra
A brand name for one of the Macintosh series of computers.
quadrature
(Q). At 90 degrees to a reference.
quadrature amplitude modulation
(QAM). A technique of modulation in which there are sixteen possible four-bit patterns, determined by the combination of phase and amplitude.
quadrillion
One thousand trillion or 10^15 (U.S. and Canada); 10^24 (Europe).
Quake
A 3D simulation game published and developed by id Software. The game is similar to DOOM or Hexen, with monsters to fight, armor, and weapons such as axes, nailguns, and shotguns. The game is built to be used with the Pentium processor and has 32-bit action. The graphics in Quake are detailed and realistic, and range from low resolution VGA to high resolution SVGA. The creatures in Quake are fairly intelligent. There are also realistic sound effects, and a musical score. A limited version of Quake can be downloaded as shareware.
Qualcomm
The California company that developed Eudora, a popular email program for Macintosh and PC, and Omnitracs, a tractor-trailer tracking system.
qualified name
A name given to something which includes the class to which it belongs in a classification system.
quality assurance
(QA). Procedures taken to ensure that a company delivers products that conform to standards.
quantifier
One that quantifies; in mathematics or logic, a prefixed operator which states for which values of a variable a formula is true.
quantum computing
Applying the principles of quantum mechanics to computer technology. If the concept of quantum computing can be made practical, it will make computers of the future much faster than those of today.
Quantum Leap
(QL). A personal computer developed by Sir Clive Sinclair and first released in 1983. It is based on the Motorola 68008 microprocessor and uses an operating system called QDOS developed by Sinclair.
QuarkXpress
A page layout program from Quark, Inc., for Macintosh and Windows.
Quarter Inch Cartridge – Extended
(QIC-EX). These magnetic tape cartridges come in both .25″ and .315″ formats and contain longer tape to extend the storage capacity of the quarter inch tape drives.
quarter inch cartridge drive
(QIC drive). A drive used to back up personal computer data on quarter inch cartridges.
quarter inch cartridge tape
(QIC tape). A magnetic tape used for backing up data, which comes in hard cartridges. QIC tape comes in minicartridges (3.5″) and data cartridges (5.25″). There are various types of cartridges and lengths of tape, storing from 40 megabytes to 25 gigabytes of data.
quarter inch cartridge wide
(QIC Wide). A quarter inch cartridge tape from Sony that is wider than 1/4 inch. It is .315″ wide and has a greater recording density, thus increasing the storage capacity.
Quarterdeck Expanded Memory Manager
(QEMM). A DOS and Windows memory manager from Quarterdeck Office Systems, Santa Monica, California; used for IBM PCs with an Intel 80386 or higher processor.
quartz crystal
The material used to maintain the heartbeat of a computer. A thin slice of quartz, activated by electrical pulses, vibrates at a steady frequency.
quattuordecillion
10^45 (U.S. and Canada); 10^84 (Europe).
query
To request information from a database.
Query By Example
(QBE). A user-friendly way of querying a database that was originally developed by IBM for use with mainframes, and later adopted by many other systems. With Query By Example, an empty record is displayed and the user types in the search keys; for example, typing “New York” in the “city” field will return all records where the city is New York.
query language
A language used for querying a database or other type of file.
ques
ASCII character 63: ? , question mark.
Questel Orbit, Inc.
An online service offering medical, patent, and trademark databases, based in McClean, Virginia.
question mark
ASCII character 63: ? .
queue
A first-in first-out data structure used for lining up requests for a resource such as a printer or communications channel.
quick and dirty
Thrown together fast and therefore not with the greatest attention to detail.
Quick Time
See QuickTime.
QuickBASIC
A fast compiler of BASIC under MS-DOS; later known as MS-BASIC. Developed by Microsoft, it adds some advanced features to BASIC. A version of QuickBASIC called QBASIC, which does not produce standalone executables, is provided with later versions of MS-DOS.
QuickBooks
A Windows and Macintosh small business accounting program from Intuit, Inc., Menlo Park, California.
QuickC
Microsoft's quick-and-easy C compiler and development software.
QuickDraw
Graphics software built into the Macintosh ROM, which draws images on the screen in response to commands from applications.
Quicken
A financial management program from Intuit, Inc., Menlo Park, California, for personal and small business use. It is available for PC and Macintosh.
QuickTime
A System 7 extension for Macintosh from Apple Computer that integrates full-motion video and sound into application programs. Also available as QuickTime for Windows (QTW).
QuickTime for Windows
(QTW ). Multimedia software from Apple Computer that integrates full-motion video and sound into application programs.
QuickTime VR
QuickTime Virtual Reality. A multimedia program that allows 3-D viewing of objects on screen.
quindecillion
10^48 (U.S. and Canada); 10^90 (Europe).
quintillion
10^18 (U.S. and Canada), 10^30 (Europe).
quit
To exit a program.
quotient
The number that results from dividing the numerator of a fraction by its denominator.
quux
An indefinite noun like foo.
QWERTY keyboard
The standard typewriter or computer keyboard. The arrangement of letters originally was designed to keep fast typists from jamming the old mechanical typewriters; frequently-used keys are separated from each other. With modern keyboards there are no longer jamming problems. An alternative keyboard called the Dvorak layout was designed which has the most frequently-used keys all on the center line for faster typing, but the qwerty keyboard continues to be used because so many typists know it.
R:BASE
A relational DBMS from Microrim, Inc., Bellevue, Washington.
RACF
Resource Access Control Facility. A large system security program for IBM mainframes that checks passwords and prevents unauthorized users from accessing files.
rack
A frame or cabinet for mounting computer components.
rack mounted
Built to fit into a metal rack. Some computer components are rack mounted units.
RAD
Rapid Application Development. A way of developing a system by completing a working part, implementing it, and adding more working parts every few months, instead of waiting to finish the entire project before putting the system into use. Otherwise, changes take place so fast in the computer industry that an application can be obsolete by the time it is implemented. Development tools such as visual programming and computer-assisted software engineering help with Rapid Application Development.
RAD tool
Rapid Application Development tool. Software that speeds up the development of applications.
radio
Wireless transmission of electric signals by way of electromagnetic waves, including the use of electromagnetic waves to transmit electric impulses that carry converted sound signals.
radio buttons
A group of buttons on the computer screen of which only one
can be selected at a time (by clicking on it). Radio buttons are used a lot with interactive forms on World Wide Web pages.
radio frequency
(RF). Electromagnetic frequencies in the range extending from below 3 kiloherz to 300 gigahertz, which includes radio and television transmission. These frequencies are above audio signals and below the frequencies of visible light.
radio frequency interference
(RFI). Interference from high-frequency electromagnetic waves emanating from electronic devices.
radio-frequency fingerprinting
An electronic fingerprint that makes it possible to identify a wireless handset by its unique radio transmission characteristics.
radiosity
A more accurate but also more process-intensive technique than raytracing, that calculates patterns of light and shadow for rendering graphics images from three-dimensional models.
radiotelephone
A device that sends telephone signals without wires, by means of radio waves.
radix
1. The base of a system of numbers; decimal numbers are radix ten, binary numbers are radix two, and hexadecimal numbers are radix sixteen. 2. The positive integer by which the value of one digit place must be multiplied to give the value of the next higher digit place; for example, in a decimal system, each digit place is multiplied by 10 to arrive at the value of the next higher digit place, so the radix is 10.
ragged left
Text in which the left margin is not aligned.
ragged right
Text in which the right margin is not aligned.
RAID
Redundant Arrays of Independent Disks (Originally “Redundant Arrays of Inexpensive Disks”). The use of two or more disk drives instead of one disk, which provides better disk performance, error recovery, and fault tolerance, and includes interleaved storage techniques and mirroring of important data. This approach was developed by a research project at the University of California, Berkeley.
RAID
Redundant Arrays of Inexpensive Disks. Comes in different levels 0,1,0+1,5, etc.
RAIDmark
A benchmark program by DynaTek Automation Systems Inc., that measures the performance of RAID arrays. RAIDmark measures cache size, system overhead, and application-level performance. There are MS-DOS and Novell versions.
RAM
Random Access Memory. The working memory of the computer. RAM is the memory used for storing data temporarily while working on it, running application programs, etc. “Random access” refers to the fact that any area of RAM can be accessed directly and immediately, in contrast to other media such as a magnetic tape where the tape must be wound to the point where the data is. RAM is called volatile memory; information in RAM will disappear if the power is switched off before it is saved to disk. There is also a form of non-volatile RAM, which must be continually energized by a battery to maintain its content. The most common form of RAM is built from semiconductor integrated circuits.
RAM cache
Random Access Memory cache. Extremely fast memory chips that help the computer to operate faster by temporarily storing frequently-accessed or recently-accessed data. Internal cache (L1) is built into the CPU; external cache (L2) is on the motherboard. When the CPU needs data, it first checks the internal cache, which is the fastest source. If the data is not there, it checks the external cache. If the data still is not found, a search of the slower RAM must be made.
RAM disk
Random Access Memory disk. A program which simulates a hard disk drive, using part of the computer's random access memory, for fast processing of data. Files can be copied into the RAM disk and edited. The RAM disk can not store files permanently; the updates must be written to the hard disk or floppy disk before the power is turned off.
RAM refresh
Random Access Memory refresh. The recharging of dynamic RAM chips, which must be refreshed hundreds of times a second in order to hold their content.
Rambus DRAM
Rambus Dynamic Random Access Memory. A high-bandwidth, high-speed DRAM from Rambus Inc. of Mountain View, California, used mainly for video accelerators.
Rambus Inc.
The Mountain View, California, company which developed Rambus DRAM.
RAMDAC
Random Access Memory Digital-to-Analog Converter. A chip that stores the color palette and converts digital information into analog signals to a color monitor. It has three analog-to-digital converters and a static RAM for storing the color palette. Each color is composed of three values representing red, green, and blue, which together make up the chosen color. Each of the three values is fed to one of the digital-to-analog converter, and the output from these three goes to the monitor to make the final color.
RAMIS
Rapid Access Management Information System. Database software from On-Line Software International.
random access
A way of storing and retrieving information in which all information locations are immediately available. For example, on a music CD any song can be selected and played randomly. A music tape, by contrast, has sequential access; to get to a particular song it is necessary to wind the tape past all the other songs before it.
random access memory
(RAM). The working memory of the computer. RAM is the memory used for storing data temporarily while working on it, running application programs, etc. “Random access” refers to the fact that any area of RAM can be accessed directly and immediately, in contrast to other media such as a magnetic tape where the tape must be wound to the point where the data is. RAM is called volatile memory; information in RAM will disappear if the power is switched off before it is saved to disk. There is also a form of non-volatile RAM, which must be continually energized by a battery to maintain its content. The most common form of RAM is built from semiconductor integrated circuits.
random access memory digital-to-analog c
(RAMDAC). A chip that stores the color palette and converts digital information into analog signals to a color monitor. It has three analog-to-digital converters and a static RAM for storing the color palette. Each color is composed of three values representing red, green, and blue, which together make up the chosen color. Each of the three values is fed to one of the digital-to-analog converter, and the output from these three goes to the monitor to make the final color.
random number generator
A software routine that generates random numbers.
ransom note typography
The use of many different fonts on a page. The expression comes from ransom notes in which the letters are cut out of newspapers and pasted together. Using too many fonts makes a page too busy, and looks unprofessional, unless the ransom note look is being used intentionally for a special effect.
Rapid Access Management Information Syst
(RAMIS). Database software from On-Line Software International.
Rapid Application Development
(RAD). A way of developing a system by completing a working part, implementing it, and adding more working parts every few months, instead of waiting to finish the entire project before putting the system into use. Otherwise, changes take place so fast in the computer industry that an application can be obsolete by the time it is implemented. Development tools such as visual programming and computer-assisted software engineering help with Rapid Application Development.
rapid prototyping
Creating a quick prototype of a software project for demonstration purposes, which can be refined later.
RARE
European Association of Research Networks. See TERENA.
RARP
Reverse Address Resolution Protocol. The opposite of Address Resolution Protocol (ARP). RARP uses a computer's hardware address to find its Internet address. It is mainly used by diskless workstations.
raster
1. The scan pattern on a display screen, in which the area is scanned from side to side in horizontal lines and from top to bottom by an electron beam. 2. A bitmapped graphic.
raster burn
1. Eyestrain from staring at a computer screen for too long; this can happen sooner with a poor quality display or have a glare on the screen. 2. Damage to a computer screen caused by leaving it on for long hours without a screen saver.
raster display
A display such as the computer screen or television screen, in which the images are formed by a scanning electron beam that moves in horizontal lines from side to side and top to bottom of the screen. The images on a raster display are made up of many tiny dots.
raster font
A bitmapped font. A font in which each character is formed from pixels arranged to make the shape of the character. Such an arrangement of pixels is called a bitmap.
raster graphics
Bitmapped graphics; computer graphics in which the image is made up of tiny dots, called pixels.
raster image processor
(RIP). Hardware, software, or both which prepares images for output in rasterized format on the computer screen or printer.
raster pattern generator
(RPG). The set of electronic circuits that convert raster patterns into bit patterns.
rasterize
To convert images into raster (bitmap) form for display or printing. Vector graphics, and vector and outline fonts must be rasterized for printing or display; all output of a display screen or printer is in raster format.
rational number
A real number that can be expressed as the quotient of an integer divided by a nonzero integer.
raw data
Unprocessed data.
raw mode
A mode that allows a computer to input or output raw data.
ray tracing
Using the computer to create a realistic graphic image by calculating the paths taken by rays of light hitting the object from various angles, thus creating reflections and shadows which give the image a three-dimensional look.
RBOC
Regional Bell Operating Company. One of seven regional telephone companies created by the divestiture of AT&T in 1984. Each of them owns two or more local telephone companies called Bell Operating Companies (BOCs). The original RBOCs were Ameritech, Bell Atlantic, BellSouth, Nynex, Pacific Telesis, SBC Communications, and U.S. West. Later SBC Communications became Southwestern Bell.
rcp
Remote copy. A UNIX utility that copies files over an Ethernet.
RD
Receiving Data. A modem status signal indicated by a flickering light on the modem, which means the local modem is receiving data from a remote computer.
rdb
A UNIX program that can be used to create a database or spreadsheet.
RDBMS
Relational Database Management System. A system for database management of a relational database. See relational database and database management system (DBMS).
RDF
Resource Description Framework. A specification being developed by the W3C to provide an infrastructure to support metadata on the Internet and WWW. For example, using RDF, data about a Web page could be divided into a main subject, secondary subjects, date of creation, name of author, etc. Putting this data into fields (which can be indicated by XML tags) would allow search engines to do smarter searches. A search engine could find, for example, all documents written by a particular author before a given date, on a specific subject. RDF does not specify names for the fields, but defines the syntax for how different fields relate to Web pages and to one another. Other examples of how RDF could be used include sitemaps, content ratings, digital libraries, and distributed authoring.
rdram
Rambus Ram
rdram
Rambus Ram
read
To input data from a storage device, a data medium, or any other source.
read cycle
The cycle in which data is read from memory.
read error
A failure to read data properly.
read news
(rn). A newsreader for an Internet newsgroup.
read only
Able to be read but not changed. A read only file or disk can be read but not edited. For example, read only memory (ROM) or CD-ROM.
read-only memory
(ROM). Memory that can be read but not changed. Read-only memory is non-volatile storage; it holds its contents even when the power is turned off. Data is placed in ROM only once, and stays there permanently. ROM chips are used for storage of the essential software of the computer, called firmware. Some kinds of ROM are PROM, EPROM, EEPROM, and CD-ROM.
read/write head
The part of a drive that reads and writes information on a disk or tape.
read/write memory
A kind of memory that can be read or written; random access memory.
README file
A text file that comes with some software and gives information on the program, often additional information not in the manual.
Ready, Set, Go
A Macintosh page layout program.
Real Audio
See RealAudio.
real estate
Computer jargon for an area of space, such as the area on the surface of a computer chip or the area available on a desktop.
real number
Any rational or irrational number; a number that corresponds to a point on a number line.
real soon now
(RSN). A slightly sarcastic expression which means probably not so soon, or maybe never.
real time
Able to respond immediately; this term refers to a system which must respond to external events, such as process control at a manufacturing plant or an embedded system that runs a piece of equipment.
real-time chat
Live back-and-forth conversation on the Internet by means of typing on the computer keyboard. Real-time means the participating users are getting the messages and responding to each other immediately, as opposed to messages sent back and forth by email.
real-time clock
A circuit within a computer that keeps track of the date and time. Usually, the real-time clock is powered by a battery so it keeps running when the computer is turned off.
real-time compression
Compression and decompression that is immediate; there is no apparent time lag for compressing or decompressing as files are opened or transmitted.
Real-Time Engineering Environment
(RTEE). Computer Aided Software Engineering (CASE) tools from Westmount.
real-time operating system
(RTOS). An operating system that works in a real-time computing environment.
real-time simulation
Simulation of events in the time frame in which they would naturally happen; for example, aircraft flight simulation is used to train pilots. See simulation.
RealAudio
Software which makes it possible to play radio and sound files over the Internet. RealAudio client software can be downloaded for free, and is used as a plug-in with web browsers like Netscape, Mosaic, and Internet Explorer. RealAudio server software is available for many platforms. Talk, music, and live radio can be heard using RealAudio.
reassembly
The restoration of a fragmented IP packet into its previous form after sending it over a network.
reboot
A warm boot, or a boot after the computer has not been turned off for long.
rec
Top-level newsgroup category for a recreational newsgroup.
receive only terminal
RO terminal. A terminal that has printing capability only, and does not have a keyboard.
receiver
A device that receives a signal.
Recommended Standard
(RS). One of a set of standards from the Electronics Industries Association for hardware devices and their interfaces. RS-232 is a well-known standard for transmitting serial data by wire.
Recommended Standard-232
(RS-232). An Electronics Industries Association standard asynchronous serial line which is used commonly for modems, computer terminals, and serial printers. RS-232 uses a 25-pin or 9-pin connector. The standard designates the purpose for each of the 25 or 9 lines, including lines for sending and receiving data, ground connections, and control lines. However, often not all of the lines are used. Some connections use only three: one for data in each direction, and one for a ground. Data sent over RS-232 is a stream of bits at a constant speed. Each character is preceded by a start bit and followed by one or two stop bits; a positive voltage is transmitted for a 0 bit, a negative voltage for a 1. RS-232 is normally used for short distances; the maximum distance with high-quality cable would be several hundred feet. The standard is now officially called EIA-232D, but RS-232 is the name in common use.
record
In a database, a group of fields that make up one complete entry. A record about a customer might contain fields for name, address, telephone, etc. A group of records makes up a file.
record head
A device that records signals onto a magnetic tape.
record layout
The way a record is formatted, including placement, order, type, and size of fields, checkboxes, and other features.
record separator
(RS). A character used to identify a logical boundary between adjacent records. Often it is ASCII character 30: Control^ .
recordable drive
A drive that reads CD-ROMs and audio CDs, and can record on CD-ROMs.
recover
To bring back a file that accidentally got deleted. There are programs designed to help recover files, such as Norton Utilities. The best idea is to have a backup copy.
rectifier
A device that converts alternating current into direct current.
recursive
Referring back to itself. See recursive.
recycle bin
On a Windows desktop, the recycle bin is like a trash basket where unneeded files can be thrown away. Dragging a file into the recycle bin removes it from its former place on the computer, and emptying the recyle bin deletes all the files in the bin.
Reduced Instruction Set Computer Operati
(RISC OS). A RISC-based operating system developed by Acorn Computer for the Archimedes personal computers. The system has a graphical user interface and command line interpreter, and supports cooperative multitasking.
Reduced Instruction Set Computing
(RISC). A microprocessor design which is intended to make operations run faster by processing a few simple instructions rather than many complex ones. CISC (complex instruction set computing) processors do more of the processing of complex operations within the CPU than RISC processors, which require certain operations to be performed by the software before the data gets to the CPU. The operating system must be set up for RISC, and the applications used must be compiled specifically for RISC architecture, otherwise the RISC processor must emulate a CISC processor, and the benefits of RISC are lost. Examples of computers with RISC architecture are the IBM RISC Sytem/6000, the PowerPC, and the PowerMac.
Redundant Arrays of Independent Disks
(RAID) Originally “Redundant Arrays of Inexpensive Disks”. The use of two or more disk drives instead of one disk, which provides better disk performance, error recovery, and fault tolerance, and includes interleaved storage techniques and mirroring of important data. This approach was developed by a research project at the University of California, Berkeley.
reformat
To reinitialize a hard or floppy disk, which erases all the data on it.
refresh rate
The maximum number of frames per second that a computer monitor can display, expressed in hertz. Each frame begins with the electron gun at the upper left corner of the screen. An electron beam is scanned horizontally across the screen, making one line; it moves down slightly to make the next line, and continues until it reaches the bottom. The electron gun returns to the upper left corner to begin the next frame. Too low a refresh rate causes a flickering screen which is hard on the eyes.
Regional Bell Operating Company
(RBOC). One of seven regional telephone companies created by the divestiture of AT&T in 1984. Each of them owns two or more local telephone companies called Bell Operating Companies (BOCs). The original RBOCs were Ameritech, Bell Atlantic, BellSouth, Nynex, Pacific Telesis, SBC Communications, and U.S. West. Later SBC Communications became Southwestern Bell.
regional network
Also called mid-level network. A network on the second level of the Internet hierarchy, connecting stub networks to the backbone.
register set
The set of all a CPU's registers.
Registry
A central hierarchical database used by Windows OS to store configuration information. The Registry has information Windows continually accesses during operations, such as what types of applications are installed on the computer and what kind of document each can create. It is possible to edit the Registry. However, a computer can be disabled if there are any errors after editing the Registry.
regression testing
When making improvements on software, retesting previously tested functions to make sure adding new features has not introduced new problems.
REGS
Abbreviation for registers.
reinstall
To install software again; necessary when a program has been corrupted.
REJ
Reject. In communications, a command or response that requests data be retransmitted.
reject
(REJ). In communications, a command or response that requests data be retransmitted.
relational database
A database in the form of tables which have rows and columns to show the relationships between items, and in which information can be cross-referenced between two or more tables to generate a third table. A query language is used to search for data. If data is changed in one table, it will be changed in all related tables. A database that has only one table is called a flat file database.
relational database management system
(RDBMS). A system for database management of a relational database. See relational database and database management system (DBMS).
relational query
A query that requires cross-referencing two or more tables of a relational database.
relative address
An address in memory that is described in terms of its displacement from a base address Also called indirect address. See also absolute address.
relative cell reference
A reference to a cell in a spreadsheet, such as B3, that indicates its relationship to other cells. When a formula containing relative cell references is copied to a different cell, it maintains its relative references. For example, the formula may state that the data in cell A3 is multiplied by the data in cell A1. Since this is a relative cell reference, it means the data in the current cell is to be multiplied by the data in the cell two rows above it. If the formula is moved to cell B3, the data in cell B3 will be multiplied by the data in cell B1.
relative path
A designation of the location of a file in relation to the current working directory, as opposed to an absolute or full path which gives the exact location.
relative pathname
A pathname that is defined in relation to the current working directory
relative reference
A reference to a cell in a spreadsheet, such as B3, that indicates its relationship to other cells. When a formula containing relative references is copied to a different cell, it maintains its relative references. For example, the formula may state that the data in cell A3 is multiplied by the data in cell A1. Since this is a relative reference, it means the data in the current cell is to be multiplied by the data in the cell two rows above it. If the formula is moved to cell B3, the data in cell B3 will be multiplied by the data in cell B1.
relative vector
A vector whose end points are indicated as coordinates relative to a base address.
relcom
Top-level newsgroup category for a Russian language newsgroup.
release
1. Making a version of software available to the public. 2. A software version which has been made available to the public.
release number
The number after the decimal place in a program number such as Word 3.2, WordPerfect 6.1. A release number indicates a minor change in a program (for example, Pagemaker 4.0 to Pagemaker 4.1), whereas a version number indicates a major change (Pagemaker 4 to Pagemaker 5).
released version
A version of software which has been made available to the public.
rem
Remarks. In programming, "rem" introduces a comment made for other programmers to read which is not part of the program instructions. It can also be used to disable certain lines of code.
remedial maintenance
Maintenance service that is needed to repair problems with the computer.
Remington Rand
A business machine company responsible for many breakthroughs in computing. E. Remington and Sons began by coming out with the first commercially successful typewriter in 1873. In 1925 Remington Typewriter Company produced the first electric typewriter. The company merged with Rand Kardex in 1927 to form Remington Rand. In 1949, Remington Rand produced 409, the world’s first business computer; later sold as the Univac 60 and 120, it was the first computer used by the U.S. Internal Revenue Service. In 1950 Remington Rand acquired the Eckert-Mauchly Computer Corporation, creators of UNIVAC I. UNIVAC I was released in 1951 and became the first commercially successful computer, with about 40 sold. In 1953, Remington Rand introduced UNIVAC 1103, the first commercial computer to use random access memory (RAM). Remington Rand merged with Sperry in 1955 to form Sperry Rand.
remote
At a distance; in communications, referring to a system, application, or device that must be accessed through a network. Contrast local.
remote access concentrator
A remote access server that supports one or more T1/E1 lines. Remote access concentrators allow multiple ISDN and analog calls to come in over one port from the telephone company, allowing for higher call densities than remote access servers; they include dial-up protocols, authentication, and greater accessibility. See remote access server.
remote access server
(RAS) The host computer within a LAN that gives access to remote users using analog modems or ISDN connections via the host computer's modem. See also remote access concentrator.
remote console
A console in another location that controls a local computer.
Remote Image Protocol
(RIP). A graphics format from TeleGrafix Communications, Inc., which can transmit graphics over low-speed lines. With a communications program that supports RIP, it is possible to use graphical interfaces on a BBS, with full color and high resolution imaging. RIP is more sophisticated than its predecessor ANSI.
remote job entry
(RJE). Transmission of a batch job to a remote computer which processes the job.
remote login
Logging in to a remote computer by a program based on Telnet, to access files, etc.
remote resource
A peripheral device that is accessed through a network; for example, a printer that serves computers on a network.
remote system
Any other computer in the network with which the local computer can communicate.
Remote Write Protocol
(RWP). An Internet protocol for exchanging short messages between terminals.
removable disk
A disk that can be put in the disk drive when reading from it or writ?t, and removed when not in use. Removable disks include floppy disks, optical disks, disk cartridges, SyQuest disks, and more; new formats are always being developed.
removable hard disk
A hard disk in a portable unit that can be removed from the computer, transferred to another computer, or kept in a disk library. Removable hard disks can be used for backup or for storing or transferring very large files. Examples are the Bernoulli and SyQuest disks.
remove spots
An image-editing filter that eliminates spots from photographs and and other images. It works by removing all pixel groups below a certain size, and the picture may lose some of its detail.
rename
To change the name of a file, folder, directory, or disk.
render
To use computer graphics to draw three-dimensional objects realistically.
rendering
Realistic drawing of three-dimensional objects using computer technology.
repeat rate
The speed at which a character is repeated when its keyboard key is held down.
repeater
A device that amplifies or refreshes a stream of data transmitted over a network, so it can travel to more remote computers. Without repeaters, a transmission will deteriorate as it travels farther and farther from the source.
repeating keys
A function of most computer keyboards. Holding down a key (instead of just touching it) makes its character repeat.
repetitive strain injury
(RSI). A condition caused by repetitive movements such as typing, in combination with bad posture caused by a poorly designed work space, general job stress, etc. Symptoms are numbness, pain, or general fatigue in fingers, arms, wrists, neck, back, or shoulders. Some ways of avoiding repetitive strain injury are proper height of work tables and chairs, a chair that has good back support, a wrist support for keyboarding, and taking breaks to stretch and exercise.
Report Program Generator
(RPG). A programming language developed by IBM in the 1960s to simplify programming for business applications. RPG presents a basic structure with common elements used in all business programs, so the programmer only needs to specify the details.
Request For Comments
(RFC). A series of numbered international documents (RFC 822, RFC 1123, etc.) that set standards which are voluntarily followed by many makers of software in the Internet community. The standards are created informally by various technical experts based on experience, rather than by formal committees.
request for proposal
(RFP). A request for bids that indicates the specifications for a software project or other system needs.
Request For Technology
(RFT). A request from the Open Software Foundation for proposals for new standards.
request to send
(RTS). A modem status signal which is a communication between the local modem and the local computer. The request to send signal asks if the modem is free to receive data from the local computer, which it will then transmit to a remote computer.
required hyphen
Same as hard hyphen. A hyphen that always prints; for example, the hyphen in “cost-effective.” A soft hyphen, by contrast, will only be set when a word that is not normally hyphenated falls at the end of a line, and must be broken for proper type spacing.
requirements
Before developing new software, a statement of what capabilities it needs to have, based on the needs of the users.
requirements analysis
An analysis before installing a computer system to see what kind of hardware and software the customer needs.
RescueWare
Technology for Year 2000 computer fixes, from North Carolina Research Triangle company Relativity Technologies.
Research Systems, Inc.
(RSI). The company that distributes Interactive Data Language (IDL).
ResEdit
Resource Editor. A Macintosh utility that allows the user to modify menus, desk accessories, etc., by editing the resource fork.
reserved memory
The memory area of 640-1024 Kb on an IBM PC, which is reserved for BIOS and add-on cards.
reset button
A button that restarts a computer and clears its memory, without turning the power off and on again; sometimes a computer has to be restarted when it is not responding to commands. Not all computers have a single reset button; on some computers a combination of keyboard keys will restart the computer.
resident font
A font which is built into a printer’s read-only memory (ROM) chips. PostScript laser printers normally have a collection of resident fonts. Fonts usually included are Avant Garde, Bookman, Courier, Helvetica, New Century Schoolbook, Palatino, Symbol, Times, Zapf Chancery, and Zapf Dingbats. For each resident font, a screen font must be installed on the computer in order to display the font onscreen. Additional fonts, in which both screen font and printer font must be installed on the computer itself, are called downloadable fonts.
resilience
The ability of a system to keep working with one or more of its components malfunctioning. Also called fault tolerance.
resistance
The amount of opposition a body or substance offers to the passage of electric current through it. Resistance is measured in ohms. See Ohm's law.
resistor
A component that has electrical resistance and that is used to control the flow of current in an electronic circuit.
resolver
The software in TCP/IP that sends requests to the Domain Name Server to convert hostnames (such as www.currents.com) to Internet addresses (such as 117.134.4.2).
resource
A facility of a computing system needed in order to perform an operation or task. Resources include memory, storage, input/output units, processing units, data sets, files, and programs.
Resource Access Control Facility
(RACF). A large system security program for IBM mainframes that checks passwords and prevents unauthorized users from accessing files.
resource compiler
Software that links a resource (such as a menu, font, or dialog box) into a program in a graphical user interface.
Resource Description Framework
(RDF). A specification being developed by the W3C to provide an infrastructure to support metadata on the Internet and WWW. For example, using RDF, data about a Web page could be divided into a main subject, secondary subjects, date of creation, name of author, etc. Putting this data into fields (which can be indicated by XML tags) would allow search engines to do smarter searches. A search engine could find, for example, all documents written by a particular author before a given date, on a specific subject. RDF does not specify names for the fields, but defines the syntax for how different fields relate to Web pages and to one another. Other examples of how RDF could be used include sitemaps, content ratings, digital libraries, and distributed authoring.
resource fork
Macintosh files have two parts: the resource fork and the data fork. The data fork contains data (just as files on other computers do). The resource fork contains programming information: in a document file, it holds the formatting codes; in an application file, it contains such elements as menus, dialog boxes, icons, etc. When transferring files over a network, Macintosh files have to be compressed and transmitted differently from files with just data in them; sometimes only the data fork is sent.
resource requirements
The system elements required by a kind of software or hardware, such as amount of memory, amount of disk space, memory addresses, etc.
resource type
The category of a resource in a graphical user interface; for example, MENU (menu resource), ICON (icon resource), DLOG (dialog box), ALRT (alert box).
response time
The time it takes for a computer to respond to a user command.
restart
To start a computer again without turning the power off. Also called warm boot.
restore
To retrieve a file from backup. If a file has been accidentally erased or corrupted, it can be restored if there is a backup.
restricted function
A function of the computer that cannot be used by a particular application.
restriction
A limitation in a program's capabilities.
Restructured Extended Executor
(REXX). REXX is a high-level language designed to support personal programming, operating system command files, macros and prototyping. Originally provided by IBM as a component of the mainframe VM/CMS system, it is now available in many environments. Elegantly simple, REXX is easy to use, versatile and fast for program development, debugging and maintenance.
Retrieve
An early query language from Tymshare Corporation.
retrieve
To locate data in storage, so it can be displayed on the screen and/or processed.
retrocomputing
Emulation of outdated technology using more modern computers, sometimes done humorously.
Retrospect Express
A Macintosh backup program that automatically saves files according to a schedule programmed by the user, and remembers where the files are.
return
To press the return key on the keyboard. This action is used to put a paragraph return in the text, select items in a dialog box or close the box, or enter other information such as a search query or requested action. On some keyboards the return key is called the “enter” key.
return character
ASCII character 13. The return character ends a line or paragraph.
return key
The key on the keyboard that ends a line or paragraph, or enters a command; also called the enter key.
Reunion
A computer program for storing and handling genealogical data.
reusability
A characteristic of some programming styles or languages (for example, object-oriented programming) in which code written for one application can be reused with different applications.
reuse
To employ code written for one application in a different application.
Reverse Address Resolution Protocol
(RARP). The opposite of Address Resolution Protocol (ARP). RARP uses a computer's hardware address to find its Internet address. It is mainly used by diskless workstations.
Reverse DNS
The ability to locate a domain name using a Host IP address.
reverse Polish notation
(RPN). A way of expressing a sequence of calculations without using parentheses to show which operation must be performed first. Reverse Polish notation goes in the opposite direction from Polish notation. For example, the expression 2(4+5), which instructs the reader to add 4 + 5 and multiply by 2, would be written 2 4 5 + * in reverse Polish notation. To make the calculation, read from left to right until you find an operation, then perform the operation on the numbers immediately to the left of it, and continue to the next operation. So 2 4 5 + * becomes 2 9 * and then 18. See also Polish notation.
revision
A release of software which has only minor changes from the previous version.
revolutions per minute
(rpm). The speed at which a disk drive rotates is measured in revolutions per minute.
rewritable
Able to be rewritten many times; for example, storage media such as magnetic disks and tapes.
rewritable optical discs
Optical discs that can be written, erased and rewritten many times, just as magnetic disks can be. The three main recording technologies for rewritable optical discs are magneto-optical (M-O), phase change, and dye polymer.
REXX
Restructured Extended Executor. REXX is a high-level language designed to support personal programming, operating system command files, macros and prototyping. Originally provided by IBM as a component of the mainframe VM/CMS system, it is now available in many environments. Elegantly simple, REXX is easy to use, versatile and fast for program development, debugging and maintenance.
RF
Radio Frequency. Electromagnetic frequencies in the range extending from below 3 kiloherz to 300 gigahertz, which includes radio and television transmission. These frequencies are above audio signals and below the frequencies of visible light.
RFC
Request For Comments. A series of numbered international documents (RFC 822, RFC 1123, etc.) that set standards which are voluntarily followed by many makers of software in the Internet community. The standards are created informally by various technical experts based on experience, rather than by formal committees.
RFI
Radio Frequency Interference. Interference from high-frequency electromagnetic waves emanating from electronic devices.
RFP
Request For Proposal. A request for bids that indicates the specifications for a software project or other system needs.
RFT
Request For Technology. A request from the Open Software Foundation for proposals for new standards.
RG58
An inexpensive, quarter-inch diameter coaxial cable used for 10base2 Ethernet wiring.
RGB
Red, Green, Blue. The three primary colors of light which, mixed together in various proportions, produce all the other colors. In a color cathode ray tube three electron guns direct these three colors of light at the screen in separate beams.
RGB monitor
Red Green Blue monitor. A display screen in which separate red, green, and blue signals are used to make up the different colors on the screen. It can be an analog or digital display.
Rhealstone
A benchmark program.
RI
Ringing. A modem status signal indicated by a light on the modem, which means the telephone on the other end is ringing.
RIAA
Recording Industry Association of America.
rib site
A computer that has a high-speed connection to a backbone site, and provides regional service for email and newsgroups.
ribbon cable
A flat cable used in the computer for such purposes as internal connection to peripherals.
rich email
Email that has voice messages attached.
rich media
Presentations that communicate their messages using a combination of media; a rich media presentation may include text, graphics, animation, sound, video, etc.
rich text
Text that contains formatting codes indicating italics, bold, etc., rather than plain ASCII.
Rich Text Format
(RTF). A way of formatting text designed by Microsoft, and intended as a universal standard for exchanging documents between different programs. Special symbols indicate such characteristics as bold, italic, the formatting of paragraphs, etc. Word processing files in some programs can be saved in Rich Text Format.
right arrow
A keyboard key which has a picture on it of an arrow pointing to the right; it moves the cursor to the right on the page.
right brace
ASCII character 125: } .
right bracket
ASCII character 93: ] .
right click
Clicking the right side button on the mouse.
right justified
Aligned on the right margin; same as flush right.
right paren
ASCII character 41: ) . Also called right parenthesis.
right parenthesis
ASCII character 41: ) . Also called right paren.
rightsizing
Finding a computer system that is the right size for the user and the use to which it will be put. Compare upsizing and downsizing.
rigid disk
A hard disk.
Rio
An MP3 player from Diamond Multimedia. It is a compact portable music player capable of playing music files downloaded from the Internet or from CDs. It has 32MB of rewritable built-in flash memory which can hold about half an hour of CD-quality music (128 kbps). A 16MB external flash card can increase playing time.
Riordan's Internet Privacy Enhanced
(RIPEM). An implementation of PEM (Privacy Enhanced Mail) from Mark Riordan.
RIP
1. Routing Information Protocol. An interior gateway protocol used with TCP/IP and NetWare. It provides routing information such as what networks are accessible and the number of hops required to reach each one. 2. Remote Image Protocol. A graphics format from TeleGrafix Communications, Inc., which can transmit graphics over low-speed lines. With a communications program that supports RIP, it is possible to use graphical interfaces on a BBS, with full color and high resolution imaging. RIP is more sophisticated than its predecessor ANSI. 3. Raster Image Processor. Hardware, software, or both which prepares images for output in rasterized format on the computer screen or printer.
RIPEM
Riordan's Internet Privacy Enhanced Mail. An implementation of PEM (Privacy Enhanced Mail) from Mark Riordan.
ripper
A program that enables the user to digitally copy songs off a CD into many different formats including MP3, WAV, AIFC, and more.
ripperX
A graphical interface to CDParanoia and 8Hz-MP3 which performs CD ripping and MP3 encoding. ripperX is written in GTK. It can play downloaded files via CD, WAV and MP3 players.
ripping
Digitally extracting audio tracks from a CD which can then be stored as a file on your computer.
RISC
Reduced Instruction Set Computing. A microprocessor design which is intended to make operations run faster by processing a few simple instructions rather than many complex ones. CISC (complex instruction set computing) processors do more of the processing of complex operations within the CPU than RISC processors, which require certain operations to be performed by the software before the data gets to the CPU. The operating system must be set up for RISC, and the applications used must be compiled specifically for RISC architecture, otherwise the RISC processor must emulate a CISC processor, and the benefits of RISC are lost. Examples of computers with RISC architecture are the IBM RISC Sytem/6000, the PowerPC, and the PowerMac.
RISC OS
Reduced Instruction Set Computer Operating System. A RISC-based operating system developed by Acorn Computer for the Archimedes personal computers. The system has a graphical user interface and command line interpreter, and supports cooperative multitasking.
RISC PC
A RISC-based personal computer from Acorn Computers.
RISC Technology Personal Computer
RT-PC. The first RISC-based UNIX computer from IBM.
Ritchie, Dennis
One of the developers of UNIX.
RJ-11
The standard telephone jack used in North America for plugging a telephone or modem into the wall.
RJ-45
A serial connector used with Ethernet and Token Ring devices that looks like a telephone jack but has eight wires instead of four or six.
RJE
Remote Job Entry. Transmission of a batch job to a remote computer which processes the job.
RKM
Rom Kernel Manual. A series of publications containing information about the Amiga operating system kernel, for use by software developers.
RLE
Run-Length Encoding. A data compression technique that substitutes a single character and a number for a run of identical characters; for example 17* would represent a run of 17 asterisks.
rlogin
Remote login. A UNIX utility that allows a user to log in to a remote host on a network as if it were directly connected, and make use of various services.
rm
A UNIX command to delete (remove) a file.
RMAIL
A mail user agent written for Emacs.
RMB
Right Mouse Button.
RMC
Right Mouse Click.
rmdir
A UNIX command to delete (remove) a directory. The directory must be empty.
RMON
Remote Monitor or Remote Monitoring.
rn
(read news). A newsreader for an Internet newsgroup.
RNG
Ringing. A modem status signal indicated by a light on the modem, which means the telephone on the other end is ringing.
RO terminal
Receive Only terminal. A terminal that has printing capability only, and does not have a keyboard.
RoboCup
An international effort to advance the science of artificial intelligence and robotics by building a team of robot soccer players that can beat a human World Cup champion team. Five-robot teams compete in front of spectators; the robot designers describe the technology they used to get the competitive edge. The largest robots are about 18 inches in diameter.
robot
1. A mechanical device that performs a task that would otherwise be done by a human. Robots can be useful for jobs that are boring or dangerous for humans to perform. The simplest robots are capable only of repeating a programmed motion; the most sophisticated models can use sensors and artificial intelligence to distinguish between objects, understand natural language, and make decisions. Robots can be programmed or operated by remote control. 2. A computer program that performs intelligent tasks such as retrieving World Wide Web documents and indexing references. 3. A program that performs a programmed communication function such as automated email answering, responding to newsgroup message, or regulatory functions in IRC, graphical chat, and other online environments.
robotics
The design, manufacture, and use of robots.
robust
Referring to a system that holds up well under exceptional conditions.
Rockwell International
An international company based in Seal Beach, California, composed of leading businesses in industrial automation, semiconductor systems, avionics and communications systems, and automotive component systems. Rockwell has pioneered technology in microprocessors, factory automation controls and motors, radios, advanced aircraft and space vehicles, advanced communications systems and Global Positioning Systems (GPS).
Rockwell Protocol Interface
(RPI). A feature in some modems that allows data compression and error correction to be performed by software instead of hardware.
Rocky Mountain Basic
A form of BASIC used on the Hewlett Packard 680×0-based systems.
rococo
Too elaborate; having too many unnecessary and resource-consuming enhancements; used in computing terminology to refer to programs that are overcomplicated, overdeveloped, and unwieldy.
rogue
A popular Dungeons-and-Dragons-style game played on UNIX systems, which has been the inspiration for many other computer adventure games.
rogue Website
A website that performs some illegal or malicious activity such as stealing passwords or downloading a virus or Trojan Horse to the user's computer.
role playing game
(RPG). A game which may be played on computer or with pen and paper, in which the players act out a different reality. Classic role-playing games involve creating a character, assigning a set of attributes such as strength, dexterity, willpower, charisma, etc., and moving the character through adventures in a fantasy, historical, or futuristic environment, usually containing enemies to fight and treasures to find. The game is often led by a gamemaster or dungeonmaster who does not play a character but who has keys to the game, hidden rules, and a secret map that the players can't see; the gamemaster tells a player what each room looks like upon entering, when he has run into something invisible, whether he hit the dragon enough times to kill it, etc. The first gamemaster is usually the designer of the game.
rollback
A feature in database management systems that undoes the last transaction and returns the database to the way it was before the change; performed automatically when a transaction is interrupted by machine error.
ROM
Read-Only Memory. Memory that can be read but not changed. Read-only memory is non-volatile storage; it holds its contents even when the power is turned off. Data is placed in ROM only once, and stays there permanently. ROM chips are used for storage of the essential software of the computer, called firmware. Some kinds of ROM are PROM, EPROM, EEPROM, and CD-ROM.
Rom Kernel Manual
(RKM). A series of publications containing information about the Amiga operating system kernel, for use by software developers.
Roman type
A style of type modeled after the engraved letters of ancient Rome. Examples of Roman typefaces are Times Roman and Palatino. Roman type has proportionally spaced letters and serifs, and is the most readable type. It is the most common type used for the text of books and newspapers.
root directory
The top level in a hierarchical filing system, which comes up when the computer is first turned on. On a PC the root directory is called C:. Other directories branch down from the root directory.
rot13
An encryption method in which each letter is replaced with the one 13 letters away from it in the alphabet. Because there are 26 letters in the alphabet, the same program can be used to encode and decode. It is often employed on Usenet.
rotational latency
The time it takes for a sector on a disk to rotate to the right position under the read/write head, so that the requested data can be retrieved. Rotational latency is one part of access time, the total amount of time it takes a computer to access an item of data.
round tape
Standard half-inch magnetic tape which is on round reels, as opposed to square tape which is in cartridges.
round-trip time
(RTT). The time it takes to send a packet to a remote host and receive a response; used to measure delay on a network at a given time.
router
A device that finds the best path for a data packet to be sent from one network to another. A router stores and forwards electronic messages between networks, first determining all possible paths to the destination address and then picking the most expedient route, based on the traffic load and the number of hops. A router works at the network layer (layer 3 of the OSI model); a bridge works at the data link layer (layer 2). A router does more processing than a bridge does. A router can be hardware or a combination of hardware and software.
routers
Specialized computers that store and forward data packets between networks, first determining all possible paths to the destination address and then picking the best route based on traffic load and number of hops. A router can be a hardware device or a combination of hardware and software.
Routing Information Protocol
(RIP). An interior gateway protocol used with TCP/IP and NetWare. It provides routing information such as what networks are accessible and the number of hops required to reach each one.
row
A horizontal set of data, as in a table or spreadsheet. The vertical set of data is called a column.
row A
The bottom row on a keyboard, which has the space bar and control keys.
row B
The lower letter row on a keyboard (second row from the bottom).
row C
The middle letter row on a keyboard (third row from the bottom).
row D
The upper letter row on a keyboard (fourth row from the bottom).
row E
The numeral row on a keyboard (fifth row from the bottom).
RPG
1. Role Playing Game. A game which may be played on computer or with pen and paper, in which the players act out a different reality. 2. Report Program Generator. A programming language that was developed by IBM in the 1960s to simplify programming for business applications. 3. Raster pattern generator. The set of electronic circuits that convert raster patterns into bit patterns.
RPI
Rockwell Protocol Interface. A feature in some modems that allows data compression and error correction to be performed by software instead of hardware.
rpm
Revolutions Per Minute. The speed at which a disk drive rotates is measured in revolutions per minute.
RPN
Reverse Polish Notation. A way of expressing a sequence of calculations without using parentheses to show which operation must be performed first. Reverse Polish notation goes in the opposite direction from Polish notation. For example, the expression 2(4+5), which instructs the reader to add 4 + 5 and multiply by 2, would be written 2 4 5 + * in reverse Polish notation. To make the calculation, read from left to right until you find an operation, then perform the operation on the numbers immediately to the left of it, and continue to the next operation. So 2 4 5 + * becomes 2 9 * and then 18. See also Polish notation.
RR
Real Reality; as opposed to VR, Virtual Reality.
RS
1. Recommended Standard. One of a set of standards from the Electronics Industries Association for hardware devices and their interfaces. RS-232 is a well-known standard for transmitting serial data by wire. 2. Record Separator. 3. Request To Send. A modem status signal which is a communication between the local modem and the local computer. The request to send signal asks if the modem is free to receive data from the local computer, which it will then transmit to a remote computer.
RS-232
(Recommended Standard-232). An Electronics Industries Association standard asynchronous serial line which is used commonly for modems, computer terminals, and serial printers. RS-232 uses a 25-pin or 9-pin connector. The standard designates the purpose for each of the 25 or 9 lines, including lines for sending and receiving data, ground connections, and control lines. However, often not all of the lines are used. Some connections use only three: one for data in each direction, and one for a ground. Data sent over RS-232 is a stream of bits at a constant speed. Each character is preceded by a start bit and followed by one or two stop bits; a positive voltage is transmitted for a 0 bit, a negative voltage for a 1. RS-232 is normally used for short distances; the maximum distance with high-quality cable would be several hundred feet. The standard is now officially called EIA-232D, but RS-232 is the name in common use.
RSI
1. Repetitive Strain Injury. 2. Research Systems, Inc. The company that distributes Interactive Data Language (IDL).
RT-PC
RISC Technology Personal Computer. The first RISC-based UNIX computer from IBM.
RTEE
Real Time Engineering Environment. Computer Aided Software Engineering (CASE) tools from Westmount.
RTF
Rich Text Format. A way of formatting text designed by Microsoft, and intended as a universal standard for exchanging documents between different programs. Special symbols indicate such characteristics as bold, italic, the formatting of paragraphs, etc. Word processing files in some programs can be saved in Rich Text Format.
RTOS
Real Time Operating System. An operating system that works in a real-time computing environment.
RTS
Request To Send. A modem status signal which is a communication between the local modem and the local computer. The request to send signal asks if the modem is free to receive data from the local computer, which it will then transmit to a remote computer.
RTT
Round-Trip Time. The time it takes to send a packet to a remote host and receive a response; used to measure delay on a network at a given time.
RTTY
Radio teletypewriter.
run native
To run in native mode, rather than in emulation mode. Software written for a particular type of computer will run faster on it than software which was written for another type of computer and must be run by emulation.
run time
(noun). 1. The time during which a process is being run. 2. The amount of time it takes for a process to execute, excluding load time, interruption by other processes, etc.
run-length encoding
(RLE). A data compression technique that substitutes a single character and a number for a run of identical characters; for example 17* would represent a run of 17 asterisks.
run-time
(adjective). Occuring while a program is being executed.
ruptime
A Berkeley UNIX command that brings back a status report for all hosts on the network.
Russian New Year exploit
A technique which enables a malicious outsider to gain control of a user's local machine simply by means of a visit to a website. This exploit originated in Russia under the name “'Novim Godom,” which means “Happy New Year.” It is implemented by hiding a CALL function somewhere in the HTML code for a website's frames. The CALL function can attack any PC which has Outlook 98 or Microsoft Excel 95 or 97 installed. The program does not have to be open, and the user does not even have to do anything such as opening an email attachment or executing a downloaded program, for the attack to work; a visit to the website where the exploit is installed is enough. The exploit can be used to erase files or gain access to private information, and the user may never know the attack occurred. Two Microsoft Office service upgrades and a patch to Excel, all available on the Microsoft website, will eliminate the vulnerability. Users of Netscape 4.5 are immune.
rwho
A Berkeley UNIX command that brings back a report of who is logged in for all hosts on the local network.
RWP
Remote Write Protocol. An Internet protocol for exchanging short messages between terminals.
RXD
Receiving Data. A modem status signal indicated by a light on the modem, which means the local modem is receiving data.
S-MIME
(Secure MIME). A public-key encryption protocol for MIME (Multipurpose Internet Mail Extensions) attachments to electronic mail messages.
S-Video
Short for Super Video. A high-quality method of transmitting video signals over cable to a television from a device such as a Camcorder VCR or game machine. S-Video separates information into two signals: Chrominance (separates color information) and Luminance (brightness). This prevents color bleeding and dot crawl, and increases clarity and sharpness. Once the information is finally delivered to the TV it is done so as a single signal over one wire. S-Video requires an S-Video input jack on the television receiving video information, support for S-Video output on the device sending signals, and a special S-Video cable.
S/N ratio
Signal-to-Noise Ratio. The amount of communication signal in relation to the amount of interference, or noise, on the medium. It is usually expressed in decibels.
s/w
Software; the programs that tell a computer what to do. Hardware is the physical part of a computer system; the machinery and equipment.
SAA
Systems Application Architecture. A set of interfaces, guidelines, and protocols developed by IBM to encourage the development of software that is consistent regardless of hardware or operating system. SAA governs user interfaces, communications protocols, programming languages, and procedure libraries.
SAD
Systems Analysis Definition. The beginning step of systems analysis, in which the end user's requirements are defined in order to get an idea of what kind of system must be designed to meet those needs.
safety-critical system
A system in which safety is critical; a computer or other system which may cause deaths if it fails. An example would be the system that controls an airplane or a network of trains. These systems must be designed to exact specifications, and with extra components in case a component fails.
sag
A temporary drop in voltage; it may cause a problem in the computer.
SAGE
Systems Administrators Guild. A special technical group of the USENIX Association, a body which focuses on research and innovation in UNIX and open systems.
SAM
Symantec AntiVirus for Macintosh. An antivirus program from Symantec Corporation, Cupertino, California.
sampling
Taking the value of a signal at evenly spaced moments in time. This is the first of three steps in converting an analog signal into a digital one. After sampling, the signals must be quantized, then encoded.
sampling rate
Sampling (taking the value of a signal at evenly spaced moments in time) is one of the steps in converting an analog signal to a digital signal. The sampling rate is the frequency at which samples are taken. The sampling rate has to be twice the rate of the analog frequency that is captured, or more; the higher the sampling rate, the better quality signal.
An IBM project to create a common foundation for developers through object technology-based business applications and Java.
sanity check
A review of a program's code to make sure there are no minor errors (such as entering the wrong character, forgetting to close parentheses, etc.) before checking the more complex logic aspects of the program.
sans serif
Without serifs, which are the short lines at the tops and bottoms of each stroke in a letter. (Sans means without in French). Sans serif typefaces are very simple; all caps sans serif lettering is called block lettering. Some examples of sans serif fonts are Helvetica, Avant Garde, and Oracle. Sans serif type is often used for headlines, signs, and ads.
Santa Cruz Operation
(SCO). A worldwide company based in Santa Cruz, California that specializes in UNIX operating systems. Some of its products are XENIX, Open Server, and Open Desktop.
SAPI
1. Scheduling Application Programming Interface. An application programming interface for business scheduling software such as Microsoft Schedule+. 2. Speech Application Programming Interface. An application programming interface from Microsoft that enables speech synthesis and speech recognition programs to communicate with the Windows 95 operating system.
sat
A nickname for satellite.
SATA
Serial ATA. Opposed to parallel ATA. Used in Storage.
SATA
Serial ATA. Opposed to parallel ATA. Used in Storage.
SATAN
Security Administrator Tool for Analyzing Networks. A freeware utility written by Dan Farmer and Wietse Venema that can be used to check a system for security vulnerabilities via the Internet.
satellite channel
A carrier frequency employed for satellite communications.
satellite link
A communications signal that goes from the earth to a satellite and back to earth.
save
To store a file on a disk or other storage medium. When a file is being edited, the changes are only in temporary memory (RAM), and will be lost when the power is shut off. To keep the changes in permanent memory, the file must be saved. It is a good idea to save often when working on a file, because if there is a power failure or the computer has to be restarted, all data not saved will be lost.
Save As
A command used to make a copy of a file, giving the copy a different name. The command “Save As” can be selected from the File menu.
Savvy Search
An experimental search system (http://guaraldi.cs.colostate.edu:2000/form) designed to query multiple Internet search engines simultaneously. Savvy Search provides multiple language versions of its search pages in at least sixteen languages.
SBC
Single Board Computer
Sbus
A bus developed by Sun Microsystems, now an IEEE (Institute of Electrical and Electronics Engineers) standard.
SC connector
A type of connector for fiber-optic cable that uses a plug and socket with a push-pull latch and has been used with FDDI, Fiber Channel and B/ISDN.
SCADA
SCADA (supervisory control and data acquisition) is a software program that gathers real time information for process control of equipment. SCADA can be used in industries such as telecommunications, oil and gas refining, water and waste control and transportation. The SCADA system gathers information, for example, about the location of a leak as well as determining how critical it is. The system will also organize and process the information, displaying it for users.
scalability
Ability to easily change in size or configuration to suit changing conditions. For example, a company that plans to set up a client/server network may want to have a system that not only works with the number of people who will immediately use the system, but the number who may be using it in one year, five years, or ten years.
scalable
Able to be changed in size or configuration to suit changing conditions. For example, a company that plans to set up a client/server network may want to have a system that not only works with the number of people who will immediately use the system, but the number who may be using it in one year, five years, or ten years.
scalable font
A font that can be used to print characters of any size. In a scalable font, the outlines of the characters are stored as vector graphics, rather than having a bitmap of each character. Because the outline can be scaled to any size and then filled in with dots, all sizes will print with the same quality. Examples of scalable fonts are the Adobe Type 1 PostScript fonts, TrueType fonts, Intellifont typefaces, and Speedo fonts.
Scalable Processor Architecture
(SPARC®). A high-speed RISC microprocessor developed by Sun Microsystems. It is used in Sun workstations, and has been adopted by some other computer manufacturers.
"SPARC® is a registered trademark of SPARC International, Inc. in the U.S. and other countries."
scalar
A single number, value, or data item, as opposed to a vector, matrix, or array (which contain multiple values).
ScanJet
A family of desktop scanners from Hewlett Packard, available in black and white or color models.
scanner
An input device that reads images or text and converts the data into digital signals. Graphical scanners read photos or other images into the computer and digitize them, producing bitmapped graphics files. Text scanners use optical character recognition software to read pages of text and produce editable text files. Bar code scanners, as used in stores, convert bar codes into digital information. Some types of scanners are flatbed scanners, sheet-fed scanners, hand-held scanners, and slide scanners.
scanners
There are many kinds of scanners. Graphical scanners read photos or other images into the computer and digitize them, producing bitmapped graphics files. Text scanners use optical character recognition software to read pages of text and produce editable text files. Bar code scanners, as used in stores, convert bar codes into digital information. See also flatbed scanner, sheet-fed scanner, hand-held scanner, and slide scanner.
scanno
A scanning error (as a typo is a typing error), caused by a glitch or minor malfunction in the scanner.
Scheduling API
Scheduling Application Programming Interface (SAPI). An application programming interface for business scheduling software such as Microsoft Schedule+.
Scholes, Christopher Latham
Designer, in 1872, of the QWERTY keyboard layout.
sci
Top-level newsgroup category for a newsgroup with hard-science discussions.
SCO
Santa Cruz Operation. A worldwide company based in Santa Cruz, California that specializes in UNIX operating systems. Some of its products are XENIX, Open Server, and Open Desktop.
Scorpion
A graphics and digital video encoder chip which makes adds Internet browsing and other interactive features to a television set. The Scorpion, also called the MC92100 chip, can be used with existing sets or new products. It can be used with set-top boxes and DVDs. Users will be able to display multiple windows on the screen, watching television and browsing the Internet at the same time.
SCP-DOS
Seattle Computer Products – Disk Operating System. The original name for the disk operating system that IBM chose to run its personal computers and called PC-DOS. Microsoft produced a version called MS-DOS. Many people refer to this operating system as simply DOS.
Scrapbook
A Macintosh utility that can be used to save text, graphics, or sounds for frequent use or for transfer from one file to another. Logos or letterheads could be stored in the Scrapbook.
screen capture
Screen capture is like taking a snapshot of the computer screen and whatever is on it at the time, and usually can be done with a keyboard command. It saves the screen image to a file on the hard drive, which can be opened with a graphics program.
screen dump
Printing whatever is on the computer screen.
screen font
A font that displays typeface characters on the computer screen. A different version of the font is needed (a printer font) to send the characters to the printer. The screen font looks like the printer font of the same name, so the user can see what the file looks like before printing.
screen phone
A device that looks similar to a standard desk telephone, but is equipped with a screen and a small keyboard for World Wide Web use.
screen saver
A program which automatically displays a moving picture or pattern on the computer screen after the computer has been idle for a certain period of time. If the keyboard or mouse is touched, the working desktop screen returns. The original purpose of a screen saver was to prevent a fixed image from being burned into the phosphor of the screen, by darkening the screen and displaying moving images. Screen burn is less likely to occur with current monitors, and would take many hours. But screen savers are fun, and users can get very creative programming different effects. One of the most famous screen savers is the one with flying toasters; there are many other effects such as underwater scenes, fireworks, stars and galaxies, etc.
screen shot
A snapshot of the computer screen and whatever is on it at the time, usually taken via keyboard commands. The screen image is saved as a file on the hard drive, which can be opened with a graphics program.
ScreenCam
A program from Lotus that can be used to make movies demonstrating how software works by moving through actions on the screen. Voice can be added, and a ScreenCam player can be included with the movie file so that it runs by itself.
screened-host firewall system
A firewall architecture in which a router is used to filter incoming and outgoing connections before sending them to the firewall.
scroll
To move through a document either up and down or sideways, in a continuous and smooth movement, as if the document were being rolled like a scroll. In many programs that use a graphical interface, there are arrows and bars to the sides of files which enable scrolling; other kinds of interfaces allow scrolling by various keyboard actions.
scroll arrow
An arrow on the side or bottom of a file that helps in scrolling. The mouse can be used to click on the arrow and move one line at a time; holding down the mouse button produces continuous scrolling.
scroll bar
A bar at the bottom or side of a window which is used to scroll through a document. It has a little movable box inside it (called a thumb, or elevator). Clicking inside the scroll bar moves the screen in jumps. Sliding the little box along the bar makes it possible to move quickly move up, down, left, or right, to a chosen point in the document.
scrollable window
A window that is not fully displayed on screen but can be scrolled up, down, or sideways to reveal its contents.
scrunch
To break through security to gain unauthorized access to a private network.
SCSI
Small Computer Systems Interface. (Pronounced “scuzzy”.) A high-speed interface that can connect to a computer devices such as hard drives, CD-ROM drives, floppy drives, tape drives, scanners, and printers. It was developed by Shugart Associates (now called Seagate). SCSI can connect up to seven devices; each one is given an identification number from 0 to 7, which is set with a manual switch. Newer versions of SCSI can connect up to 15 devices. The SCSI cable transfers eight bits at a time, in parallel.
SCSIProbe
A Macintosh control panel that can be used to find and mount a SCSI device.
scuzzy
The common pronunciation for SCSI (Small Computer Systems Interface).
SD
1. Sending Data. A modem status signal indicated by a flickering light on the modem, which means the local modem is sending data to a remote computer. 2. Single Density. Refers to the early floppy disks, made before double-density and high-density formats became available.
SD RAM
Synchronous Dynamic Random Access Memory (SDRAM). High-speed DRAM that adds a separate clock signal to the control signals. SDRAM can transfer bursts of non-contiguous data at 100 MBytes/sec, and has an access time of 8-12 nanoseconds. It comes in 64-bit modules: long 168-pin DIMMs.
SDDI
Sony Digital Data Interface.
SDK
Software Development Kit or Software Developers Kit. A set of tools to help programmers write new applications. The kit usually provides tools for creating menus, icons, dialog boxes, etc., and for interfacing the application with the operating system(s) it will be used with.
SDLC
Synchronous Data Link Control. A data transfer protocol used in IBM’s SNA networks. SDLC conforms to ISO’s High-level Data Link Control (HDLC) and ANSI’s Advanced Data Communication Control Procedures (ADCCP).
SDMI
Secure Digital Music Initiative. The recording industry has become increasingly concerned as new technologies for copying and distributing music over the Internet, such as MP3, have evolved. The Secure Digital Music Initiative was established to protect music companies' copyrights on the Web. Founded by the Recording Industry Association of America (RIAA), the initiative has support from major labels such as Universal, EMI, Sony, and Time Warner. The goal of SDMI is to create an open architecture and specification for digital music security, to insure interoperability among digital products as well as protect copyrighted music in various digital formats.
SDML
Signed Document Markup Language. A specification of a generic method for digitally signing a document, a section of a document, or multiple documents together. SDML requires the use of public key cryptography and can be used with web pages, e-mail messages or any text based documents. SDML is a generalization of the Financial Services Markup Language (FSML). SDML may be used for electronic funds transfer, electronic commerce, or any other signed contract or agreement.
SDRAM
Synchronous Dynamic Random Access Memory. High-speed DRAM that adds a separate clock signal to the control signals. SDRAM can transfer bursts of non-contiguous data at 100 MBytes/sec, and has an access time of 8-12 nanoseconds. It comes in 64-bit modules: long 168-pin DIMMs.
SDSL
Synchronous Digital Subscriber Line. A digital subscriber line that sends data at the same speed in both directions. SDSL is intended for business use, whereas ADSL (asynchronous digital subscriber line), in which data downloads much faster than it uploads, is mainly for home use. See also ADSL, DSL, HDSL.
SDSL
Symmetric Digital Subscriber Line. A technology that can send data at up to 3 Mbps over ordinary copper telephone lines. SDSL sends digital pulses in the high-frequency bandwidth not used by normal voice communications, which makes it possible to have voice and data transmissions over the same wires. SDSL is called symmetric because, unlike ADSL (asymmetric digital subscriber line), it has the same data rates for transmission from server to client and from client to server. A special SDSL modem is necessary.
SEA
Self Extracting Archive. A Macintosh archive format; it creates a file which automatically expands when a user double-clicks on its icon.
Seagate Technology, Inc.
A major independent manufacturer of hard disk drives, based in Scotts Valley, California.
search and replace
A computer function that searches for all instances of a particular set of characters and replaces it with a different set of characters determined by the user.
search engine
A program on the Internet that allows users to search for files and information.
search engines
Programs on the Internet that help users search for files and information. Examples are Infoseek, Yahoo, Lycos, Excite, and many more. Most search engines find files that contain a key word or words typed in by the user. Some search engines specialize in a subject area or type of file. Others, called meta-search engines, query a number of regular search engines and collect the best results.
search key
Data entered into a search engine indicating what the user wants to locate in its database.
Seattle Computer Products
Original developers of DOS, which was at first called SCP-DOS (Seattle Computer Products – Disk Operating System).
Seattle Computer Products – Disk Operati
(SCP-DOS). The original name for the disk operating system that IBM chose to run its personal computers and called PC-DOS. Microsoft produced a version called MS-DOS. Many people refer to this operating system as simply DOS.
SECAM
Sequential Couleurs a Memoire; also called Systeme Electronique Couleur Avec Memoire. The television broadcast standard used in France, the Middle East, and most of Eastern Europe. SECAM broadcasts an analog signal at 819 lines of resolution 25 interlaced frames a second, and uses sequential encoding of primary colors in alternating scan lines. PAL is the standard used in England and the rest of Europe; NTSC is used in the United States and Japan.
SECDEC
Single Error Correction, Double Error Detection.
second generation computer
A computer built with discrete transistors. Second-generation computers were made in the mid-1950s through mid-1960s.
second generation language
Assembly language; the language in between machine language and high-level programming languages.
secondary storage
Storage other than the computer's internal memory (RAM); external storage, such as disk or magnetic tape.
secret key encryption
A form of cryptography in which sender and receiver share a secret key.
sectors per track
(spt). Disk storage is organized in sectors, which are pie-shaped slices, and tracks, which are concentric rings. A combination of two or more sectors on a single track makes a cluster or block, the minimum unit used to store information. The number of sectors per track determines the size of each cluster. The number of clusters on a disk's surface determines the storage capacity of the disk. The number of sectors per track is also related to the speed at which a disk is read and the pattern of sector mapping.
Secure Digital Music Initiative
(SDMI). The recording industry has become increasingly concerned as new technologies for copying and distributing music over the Internet, such as MP3, have evolved. The Secure Digital Music Initiative was established to protect music companies' copyrights on the Web. Founded by the Recording Industry Association of America (RIAA), the initiative has support from major labels such as Universal, EMI, Sony, and Time Warner. The goal of SDMI is to create an open architecture and specification for digital music security, to insure interoperability among digital products as well as protect copyrighted music in various digital formats.
Secure MIME
(S/MIME or S-MIME). A public-key encryption protocol for MIME (Multipurpose Internet Mail Extensions) attachments to electronic mail messages.
Secure Sockets Layer
(SSL). A protocol from Netscape Communications Corporation, which is designed to provide secure communications on the Internet.
Security Administrator Tool for Analyzin
(SATAN). A freeware utility written by Dan Farmer and Wietse Venema that can be used to check a system for security vulnerabilities via the Internet.
security hole scanning
Looking for security holes in a system, usually with the intent of using the information to obtain unauthorized access.
see you see me
CU-SeeMe.
Sega
A Japanese company that manufactures popular video games and the equipment used to play them. Other products from Sega are mega-CDs, portable games, interactive products for PCs, and electronic theme parks.
select
To highlight an area of text or an image, or several items together. Areas of text can be selected with a mouse by dragging the cursor over them. Graphic elements (including text windows in a page layout program) are selected by clicking the mouse on them. Several elements can be selected together by clicking the mouse on each while holding down the shift key. Selected items can be moved or modified with other commands. On computers that do not have a mouse, the cursor is used for selecting, along with keyboard commands.
select all
A command that will select all the items on a page, or all the text within a window that the cursor is in.
selection list
A dialog box that has a scrollable list of choices from which the user can select one.
Self Extracting Archive
(SEA). A Macintosh archive format; it creates a file which automatically expands when a user double-clicks on its icon.
self-extracting file
A compressed file which automatically expands when executed. Often self-extracting files have the extension .SEA (self-extracting archive).
Semantic Web
The Web of data with meaning in the sense that a computer program can learn enough about what the data means to process it. (Tim Berners-Lee, from his book Weaving the Web, published 1999/2000)
semicolon
ASCII character 59: ; .
send to back
A feature in a page layout or graphics program that allows a particular graphic element to be selected and sent to the background; if the objects in front of it are opaque, the object sent to the back will be hidden or partly hidden. For example, a lightly screened box might be sent to the back, with a window of text sent to the front so it will show inside the box.
send to front
A feature in a page layout or graphics program that allows a particular graphic element to be selected and brought to the foreground; if the object is opaque, objects behind it will be hidden or partly hidden. For example, a light-colored box might be placed diagonally in front of a darker-colored box of the same size, to create the effect of a shadow. The light-colored box in this example is sent to the front.
septendecillion
10^54 (U.S. and Canada); 10^102 (Europe).
septet
A seven-bit byte.
septillion
10^24 (U.S. and Canada); 10^42 (Europe).
Sequenced Packet Exchange
(SPX). A Novell NetWare communications protocol used to transmit messages reliably over a network.
Sequent Computer Systems, Inc.
A computer manufacturer in Beaverton, Oregon that develops symmetric multiprocessing systems.
sequential
In consecutive order; for example, alphabetical, by date, or by number.
sequential access
A way of storing and retrieving information in sequence. For example, on a magnetic tape, which has sequential access, to get to a piece of information it is necessary to wind the tape up to that point. On a CD-ROM, which has random access, any file can be selected and accessed immediately in any order.
Sequential Couleurs a Memoire
(SECAM). Also called Systeme Electronique Couleur Avec Memoire. The television broadcast standard used in France, the Middle East, and most of Eastern Europe. SECAM broadcasts an analog signal at 819 lines of resolution 25 interlaced frames a second, and uses sequential encoding of primary colors in alternating scan lines. PAL is the standard used in England and the rest of Europe; NTSC is used in the U.S. and Japan.
serial
One at a time. In serial transmissions, one bit at a time is sent over the serial line.
serial computer
A computer with one processor that runs only one task at a time, executing instructions one after another, as opposed to a parallel computer that can run several processes at once.
serial device
Any hardware unit that is connected to a computer by plugging it into the serial port; for example, a modem, a keyboard, or a serial printer.
serial interface
A port on the computer that transmits data in serial form, one bit at a time, as opposed to a parallel interface which sends a number of bits side by side. Within the computer, data is transmitted over parallel lines, for greater speed; but telephone lines require serial transmission. The serial interface converts data from a parallel to a serial arrangement for sending to the modem. A serial interface is also used to connect a mouse, a scanner, and certain printers.
serial line
A transmission line which connects two serial ports, over which data is sent one bit at a time. A serial line can have two wires, so data can be transmitted and received at the same time.
Serial Line Internet Protocol
(SLIP). Software which uses the Internet Protocol (TCP/IP) over a serial line. SLIP makes it possible for a computer to communicate with other computers by means of a dial-up connection; for example, a serial port hooked to a modem that makes a connection between two local area networks or is used to access the Internet and World Wide Web.
serial mouse
The common mouse that is plugged into a PC serial port.
serial number
A number that uniquely identifies each hardware device or copy of software; the serial number for software is usually called a registration number. It is important to keep track of serial numbers, which are needed when calling for tech support, service, upgrades, etc.
serial port
A socket on a computer which is usually used to connect a modem, mouse, scanner, or serial printer. Sometimes two computers are connected together by their serial ports to send data between them. A serial port, also called a male connector, has 9 or 25 pins. A serial port sends information through a cable one bit at a time, whereas a parallel port sends eight bits at a time along parallel wires. A parallel port sends data faster but a serial port is reliable for transmission over a longer distance.
serial ports
Sockets on a computer that are usually used to connect a modem, mouse, scanner, or serial printer. Sometimes two computers are connected together by their serial ports to send data between them. A serial port, also called a male connector, has 9 or 25 pins. A serial port sends information through a cable one bit at a time, whereas a parallel port sends eight bits at a time along parallel wires. A parallel port sends data faster but a serial port is reliable for transmission over a longer distance.
serial printer
A printer connected to the computer by a serial port.
serial processing
Using a single processor to run one task at a time; also called sequential processing.
serial transmission
A way of transmitting information one bit after another, as opposed to parallel transmission in which a number of bits are transmitted at one time.
serialize
To convert a parallel arrangement of data (in which a number of bits are transmitted at a time along parallel channels) into a serial form (in which one bit at a time is transmitted); a serial interface provides this conversion to enable data transmission.
serif
A short finishing stroke at the end of and at an angle to each stroke in a letter. Serifs are found in typestyles such as Times Roman, Palatino, Garamond, and Baskerville. Serifs are thought to make type more readable, and are often used in book and newspaper text. Fonts without serifs are called san serif fonts.
server
The computer in a client/server architecture that supplies files or services. The computer that requests services is called the client. The client may request file transfer, remote logins, printing, or other available services.
server application
The software used by a server in providing a service to a client.
server-side image map
An image map in which the map that relates parts of the image to different URLs is stored on the server. See server-side include.
server-side includes
(SSI). The ability to include files from the server inside an HTML document by placing tags in the HTML file that link to those files. Using server-side includes makes it unnecessary to include multiple copies of the same information in the HTML file, and make it easier to work with frequently-updated information. Server-side includes are available on some HTTP servers.
service bureau
A business that sells such services as scanning, color printing, copying, color separations, and disk format conversion.
Service Level Agreement (SLA)
A contract between a network service provider and a customer that specifies the services the network service provider will furnish. Services SLAs may specify often include the percentage of time services will be available; number of users that can be served simultaneously; help-desk response time; and statistics to be provided. ISPs often provide SLAs for its customers.
service profile identifier
(SPID). A number that identifies a user's equipment for connecting to an ISDN (Integrated Services Digital Network) line.
servlet
An applet that runs on a server, usually meaning a Java applet that runs on a Web server.
session layer
Layer 5 of the Open Systems Interconnection (OSI) networking model, which handles logical connections between hosts; creates, maintains, and terminates a session; and handles security. It is a composite of the data flow control layer and transmission control layer.
set
A collection of elements which have some characteristic or characteristics in common; for example, the set of all rational numbers, the set of all even numbers greater than 20, or the set of all positive integers.
set theory
The theory of how sets are defined and how they interact. Three important interactions between sets are complement, union, and intersection.
set-top box
(STB). A box that sits on top of a television set and is the interface between the home television and the cable TV company. New technologies evolving for set-top boxes are video-on-demand, video games, educational services, database searches, and home shopping.
seven dwarfs
Univac, Burroughs, General Electric, Honeywell, RCA, National Cash Register, and Control Data Corporation. These companies were the main competitors to IBM in the early days of computing.
seven layer model
The Open Systems Interconnection model for communication which includes the physical layer, data link layer, network layer, transport layer, session layer, presentation layer, and application layer.
severity code
A code that classifies the seriousness of an error condition.
sex changer
A coupler with two male ends used to connect two female connectors, or a coupler with two female ends used to connect two male connectors.
sexadecimal
Early word for hexadecimal, the base 16 numbering system.
sexdecillion
10^51 (U.S. and Canada); 10^96 (Europe).
sextet
A six-bit byte.
sextillion
10^21 (U.S. and Canada); 10^36 (Europe).
SGI
Silicon Graphics, Inc. A Mountain View, California manufacturer of high-end graphics workstations and software, founded by James Clark, who later became head of Mosaic Communications Corporation.
SGML
Standard Generalized Markup Language. A generic language for writing markup languages. SGML makes possible different presentations of the same information by defining the general structure and elements of a document. HTML (Hypertext Markup Language) is based on SGML.
SGML application
A markup language written in SGML; HTML is an example. SGML (Standard Generalized Markup Language) is a meta-language – a language for writing markup languages.
SGRAM
Synchronous Graphic Random Access Memory. Memory that is used for graphic-intensive operations such as 3-D rendering and displaying full-motion video.
sh
Bourne shell. An early command interpreter and script language for UNIX, by S.R. Bourne of Bell Laboratories.
shadow mask
A thin metal plate full of holes that is behind the glass of a CRT screen. Electron beams are aimed through the holes and strike the phosphor coating on the inside of the screen. The purpose of the shadow mask is to keep the electron beams exactly aligned with their targets. The holes in most shadow masks are arranged in triangles; the Sony Trinitron has holes arranged in parallel slots.
shadow RAM
Shadow Random Access Memory. In a PC, an area of RAM in which a copy of the ROM Basic Input/Output System is stored, for faster access than the BIOS on the ROM chip.
Share and enjoy!
A statement found at the end of a README file for software, which means the software can be freely distributed and used.
shared logic
An arrangement in which two or more terminals close to each other share a computer that does the processing. Shared logic is commonly used with word processing applications.
shared resource
A peripheral device which is shared by more than one computer, such as a printer, disk, etc.
Shared Time Repair of Big Electronic Sys
(STROBES). A programming language used in testing computers.
shareware
Software that is copyrighted, but may be downloaded and used for a limited time for free, after which the user is asked to voluntarily send the author a small payment. Some shareware products offer additional features, documentation, technical support, and/or updates to registered users.
sharp
ASCII character 35: # . Also called hash mark or pound.
sheet feeder
A mechanical device attached to a printer which automatically feeds sheets of paper or forms from an input drawer into the printer, and which feeds the finished printed pages into an output drawer. Most printing instructions allow a choice between using the sheet feeder or the manual feed.
sheet-fed scanner
A scanner that feeds each sheet of paper across a nonmoving scan head; this is different from the flatbed scanner in which the paper is laid on a sheet of glass and the scan head moves. Obviously, a sheet-fed scanner can not be used to scan pages in books or magazines, or pages with pasted-on items.
shelf life
The period of time a material can “sit on the shelf” before it deteriorates and cannot be used.
shelfware
Software that gets bought by a company or individual that ends up sitting on a shelf somewhere and not being used.
shell
A software interface between the user and the computer's operating system. The shell interprets commands entered by the user, and passes them on to the operating system. DOS shells are COMMAND.COM and DOS shell; some UNIX shells are the Bourne shell (sh), the C shell (csh), and the Korn shell (ksh).
shell account
A dialup account with an Internet Service Provider that is based on a UNIX command-line interface.
shell extension
A computer’s shell is that part of the operating system that allows the user to access and manipulate the components of the computer’s hardware and software. A shell extension is a small system utility that allows a user to more easily access and configure the computer’s workings by tweaking the settings of the operating system.
shell script
A file containing commands to be carried out by the shell (the interface that passes commands to the operating system).
Sherlock
The name of the Find feature first used in Mac OS 8.5. It is used for locating files on the local computer, but also includes the ability to search any site on the Web that has a search engine. To use Sherlock to search a website, the user must place a plug-in file for the site in the Internet Search Sites folder of the System Folder.
SHF
Super High Frequency. Electromagnetic frequencies in the range of 3 to 30 gigaherz.
shielded twisted pair
(STP). Twisted pair cable that is wrapped in a metal sheath to provide extra protection from external interfering signals.
shift key
A keyboard key that, when held down, makes all the letters print as capitals, and the non-letter keys print other special characters such as the asterisk (*), ampersand (&), etc. The shift key is also used, alone or in combination with other keys, to give various commands to the computer.
shift register
A register in which all the bits can be moved one place to the left (or the right) when a particular control signal is pulsed. The shift register is used in binary multiplication and serial-parallel conversion, among other things.
Shocked
An adjective describing a Web page that uses Shockwave graphics.
Shockwave
A program, available as a plug-in, which enables a browser to view files created with Macromedia Director or Macromedia Freehand. Web pages that incorporate Shockwave effects are called “Shocked.”
Shockwave Flash
A file format for delivering interactive vector graphics and animations over the World Wide Web.
SHOE
Simple HTML Ontology Extensions. An extension to HTML which makes it possible for authors to include machine-readable semantic knowledge in World Wide Web documents. It includes mechanisms for hierarchical classification and for specifying relationships between elements and data. SHOE makes it possible for intelligent agents to gather information about web pages and other documents more intelligently, and thus to improve searching and knowledge-gathering.
short card
A PC expansion card that is half the size of a full-sized card, and fits in a short slot.
Short Messaging System
(SMS). A feature that allows users to receive or transmit short text messages using a wireless phone.
short-haul modem
A modem that can only transmit for a short distance (about a mile).
Shoutcast
Software for streaming MP3s. The official Shoutcast website has addresses for many stations which are like radio stations. You enter the URL in your MP3 player for the station you want, then the MP3s are downloaded while playing.
shouting
Using all capital letters in an email, chat or newsgroup message; CONSIDERED RUDE!
shovelware
Bonus software put on a CD-ROM to fill up extra space not needed by the main product.
show
In a graphical user interface, a menu selection that instructs the computer to show certain things on screen; for example, balloon help, the toolbox, guide lines, etc. The opposite command is “hide . . . “.
Show-And-Tell
A visual computer language for elementary school children.
ShrinkWrap
A Mac program from Aladdin that makes an exact copy of a CD, floppy, entire drive, or any type of file and turns it into a disk image on the desktop or for sending over the Internet. ShrinkWrap makes it unnecessary to load the actual CD, Zip, Jaz, SuperDrive or floppy disk; multiple CDs or disks are accessible on the desktop simultaneously.
SI
1. Systeme Internationale d'Unites, the international metric system. 2. Systems Integration. 3. Norton SI. 4. Macintosh SI.
sideband
A band of frequencies just above or just below a carrier frequency, produced by modulation of a carrier wave.
sidecar
A box attached to the outside a computer to add memory, expansion slots, hard drive controllers, or other expansions.
Sieve of Eratosthenes
An algorithm for finding prime numbers, used as a benchmark to measure the speed at which a computers does arithmetic.
SIG
Special Interest Group. A subdivision of a computer user group or other organization that meets to share information about an area of special interest. For example, SIGGRAPH is the special interest group of the Association of Computing Machinery that addresses computer graphics.
sig
Signature. A text file, usually only a few lines, which has the name of the user, and sometimes contact information, which is automatically attached to email messages and newsgroup postings. Some people include ASCII art, slogans, or favorite quotations in their signatures.
sig block
Signature (UNIX terminology). A text file, usually only a few lines, which has the name of the user, and sometimes contact information, which is automatically attached to email messages and newsgroup postings. Some people include ASCII art, slogans, or favorite quotations in their signatures.
sig quote
A quote a user puts within his or her electronic signature, which may be inspiring, humorous, opinionated, etc.
SIGARCH
The Special Interest Group for Computer Architecture of the Association of Computing Machinery.
Siggen Pro
A freeware program for generating signature files.
SIGGRAPH
A special interest group (SIG) of the Association of Computing Machinery that deals with computer graphics.
SIGhyper
A special interest group (SIG) of the SGML Users' Group that deals with hypertext and multimedia.
SIGMA
A NASA scientific program development tool.
sign off
To exit a computer system or network; same as log off.
sign on
To gain access to a computer system or network; same as log on. Signing on often requires the user to enter a password.
signal-to-noise ratio
(SNR). The amount of communication signal in relation to the amount of interference, or noise, on the medium. It is usually expressed in decibels.
signature
A text file, usually only a few lines, which has the name of the user, and sometimes contact information, which is automatically attached to email messages and newsgroup postings. Some people include ASCII art, slogans, or favorite quotations in their signatures.
Signed Document Markup Language
(SDML). A specification of a generic method for digitally signing a document, a section of a document, or multiple documents together. SDML requires the use of public key cryptography and can be used with web pages, e-mail messages or any text based documents. SDML is a generalization of the Financial Services Markup Language (FSML). SDML may be used for
electronic funds transfer, electronic commerce, or any other signed
contract or agreement.
SIGPLAN
The Special Interest Group on Programming Languages of the Association of Computing Machinery.
silicon
(Si). An element found in rocks and sand, which is used as the base, or substrate, for computer chips.
Silicon Alley
New York's equivalent of Silicon Valley; a region of many high-tech companies.
Silicon Dominion
Washington, DC's equivalent of Silicon Valley; a region of many high-tech companies.
Silicon Forest
Seattle's equivalent of Silicon Valley; a region of many high-tech companies.
Silicon Forest
The area around Seattle, Washington, where computer-related companies are located.
Silicon Graphics, Inc.
(SGI). A Mountain View, California manufacturer of high-end graphics workstations and software, founded by James Clark, who later became head of Mosaic Communications Corporation.
Silicon Hills
Austin's equivalent of Silicon Valley; a region of many high-tech companies.
silicon on sapphire
(SOS). A kind of computer chip that has a sapphire substrate covered with a thin layer of silicon.
Silicon Prairie
The area around Austin, Texas, where many hi-tech companies are located.
Silicon Valley
The area around San Jose, California, where many computer-related companies are located.
SIM
Society for Information Management. An organization for professionals in Management Information Services, formerly called Society for MIS.
SimCity
A simulation game from Maxis Software in which the object of the game is to design a city and manage it. SimCity is available for PC, Atari, Mac, Amiga, and Sun computers.
SimCity 2000
An advanced version of SimCity, the Maxis Software simulation game in which the object is to build a city and manage it well.
SIMD
Single Instruction/Multiple Data. A parallel processor that performs the same operations on different data. Also called data parallel.
SIMM
Single Inline Memory Module. A slim circuit board that holds Random Access Memory (RAM) chips. SIMMs can be plugged into sockets on the computer's motherboard to add memory to the computer. Depending on the computer, SIMMs may need to be installed in multiples of two or four.
Smallworldwide plc.
smart
In computer technology, a relative term, indicating how sophisticated a program or machine is and how many capabilities it has. A “smart missile” is one that is guided electronically, as opposed to a non-hi-tech missile; “smart modems” have more capabilities and can be programmed to make more decisions than earlier modems.
smart cable
A cable that has a microprocessor in it; it can assess incoming signals and convert them, if necessary, to the correct format.
smart card
A plastic card the size of a credit card that has an embedded microprocessor for storing information, used for banking, medical alerts, etc. It is used by inserting it into a reading device which is connected with a main computer.
smart installer
An installer that determines what configuration of software is needed by the current computer, and installs that version of the program.
smart terminal
1. A terminal that is part of a larger system and uses a main computer for storage of data, but has its own processing capability. 2. computer slang for a university.
Smartdrive
A DOS and Windows disk cache program from Microsoft. Typing SMARTDRV /S at the DOS prompt will display cache size and percentage of cache hits. The SMARTDRV line in the AUTOEXEC.BAT file can be used to set cache size.
SmartSuite
A software suite from Lotus which includes Ami Pro word processor, Lotus 1-2-3 spreadsheet, Freelance Graphics, Organizer personal information manager, and Approach database.
smash case
To automatically put all letters into uppercase or lowercase, regardless of how the text is entered. Some programs and interactive forms ignore case distinctions.
SMCC
Sun Microsystems Computer Corporation. See Sun Microsystems, Inc.
SMDS
Switched Multimegabit Data Service. A high-speed data communications service developed by Bellcore for connecting local area networks over the public telephone lines.
SMIL
Synchronized Multimedia Integration Language. A language developed by the W3C Synchronized Multimedia (SYMM) Working Group, that makes possible the broadcast of television-like content on the Web, and lowers the bandwidth needed for this kind of transmission. SMIL makes the production of audio-visual materials easy; users do not have to learn a programming language and can work with a simple text editor. SMIL uses XML syntax, and makes it possible to combine video, audio, text, graphic images, and hyperlinks.
smiley
Smiling face : ) (emoticon). Also used to refer to any emoticon.
smirkey
An emoticon that shows a smirking face, like :-, or }-) or :-} .
smoke and mirrors
Misleading marketing practices, similar to the illusions created in a magic show.
smoke test
A way of testing equipment by turning it on and seeing if it smokes.
smooth
This is a technique used by printers to make curves appear smooth. This is done by the size of the dots that make up the cure and the horizontal alingments of the dots affects the the cure by making it smooth.
SMP
Symmetric Multi-Processing. A computer system which has two or more processors connected in the same cabinet, managed by one operating system, sharing the same memory, and having equal access to input/output devices. Application programs may run on any or all processors in the system; assignment of tasks is decided by the operating system. One advantage of SMP systems is scalability; additional processors can be added as needed. However, in an SMP system, if one processor is down, the whole system is down.
SMPTE
Society for Motion Picture and TV Engineers, based in White Plains, New York. An standards organization for TV production, which developed SMPTE time code for audio and video.
SMPTE time code
Society for Motion Picture and TV Engineers time code. An eight-digit code for numbering each frame on videotape, in the form HH:MM:SS:FF (hours, minutes, seconds, frame number). SMPTE time code can be used to locate an exact frame, and to synchronize video and audio.
SMS
(Short Messaging System). A feature that allows users to receive or transmit short text messages using a wireless phone.
SMS
1. (Short Messaging System or Short Message Service). A feature that allows users to receive or transmit short text messages using a wireless phone. Using SMS, a short alphanumeric message, up to 160 characters, can be transmitted to a mobile phone, which displays the message as a pager would. 2. Storage Management Services. Software that can be used to back up data on a network by routing it to designated storage locations.
SMTP
Simple Mail Transfer Protocol. A server-to-server protocol for delivering electronic mail. The standard protocol used on the Internet; also used on other TCP/IP networks.
SMTP host
Simple Mail Transfer Protocol host. The location where outgoing electronic mail is dropped off, analogous to the mail slot at the post office.
SNA
Systems Network Architecture. A networking protocol standard for IBM mainframes and IBM-compatible mainframes.
snail mail
Regular postal service mail, which is slower than electronic mail.
snap point
One of the points on a graphic or text block that are used to snap it to a grid line or guide line. The snap points define the edges of the text or graphic element. If a snap to feature is chosen, the item will be moved so the snap points are touching the closest grid line or guide line.
snap to grid
A feature that can be selected in a draw program that automatically moves a text block or graphic element so it touches a grid line, if the grid line is within a certain distance.
snap to guides
A feature that can be selected in a page layout program that automatically moves a text block or graphic element so it touches a guide line, if the guide line is within a certain distance.
SNAP/SHOT
System Network Analysis Program / Simulated Host Overview Technique.
sneakernet
A means of moving a file from one computer to another by putting it on a floppy disk and carrying it across the room (possibly while wearing sneakers).
sniffer
A software or hardware tool that monitors data packets on a network to make sure messages are arriving as they should and everything else is working right.
SNMP
Simple Network Management Protocol. The Internet standard protocol for network management software. Using SNMP, programs called agents monitor various devices on the network (hubs, routers, bridges, etc.). Another program collects the data from the agents. The database created by the monitoring operations is called a management information base (MIB). This data is used to check if all devices on the network are operating properly.
SNMP agent
Simple Network Management Protocol agent. Hardware and/or software which is used to monitor devices on a network. Data from an SNMP agent, contained in a management information base (MIB), helps in management of the network by showing whether all devices are operating properly.
SNMP v2
Simple Network Management Protocol version 2. An updated version of SNMP which has better security, automatic continuous feedback, and other improvements.
SNOBOL
String Oriented Symbolic Language. A programming language from Bell Labs used for string processing, compiler development, and pattern matching.
snow
Small flickering white spots on a computer display, that look like snow. These spots occur temporarily when the contents of video memory are changed too rapidly for the display electronics to immediately register the new image.
SNR
Signal-to-Noise Ratio. The amount of communication signal in relation to the amount of interference, or noise, on the medium. It is usually expressed in decibels.
SO-DIMM
Small Outline Dual Inline Memory Module. A memory module that is half the size of a DIMM, and has 72 pins; often used in notebooks.
SOAP
Simple Object Access Protocol (SOAP) is a way for a program running in one kind of operating system (such as Windows 2000) to communicate with a program in the same or another kind of an operating system (such as Linux) by using the World Wide Web’s Hypertext Transfer Protocol (HTTP)and its Extensible Markup Language (XML) as the mechanisms for information exchange. SOAP specifies exactly how to encode an HTTP header and an XML file so that a program in one computer can call a program in another computer and pass it information. It also specifies how the called program can return a response.
soc
Top-level newsgroup category for a newsgroup on social issues.
social engineering
Breaking an organization’s security by interactions with people; for example, tricking someone into giving out a password.
Society for Information Management
(SIM). An organization for professionals in Management Information Services, formerly called Society for MIS.
Society for Motion Picture and TV Engine
(SMPTE). An standards organization for TV production, based in White Plains, New York, which developed SMPTE time code for audio and video.
socket
1. A hardware receptacle for a plug. 2. A communication path between two computer processes on the same machine or different machines. On a network, sockets serve as endpoints for exchanging data between computers. Each socket has a socket address, which is a port number plus a network address. Network connections are established by a socket device driver.
socket 7
The socket where the CPU is connected to the motherboard, on 486 and Pentium systems.
soft boot
Restarting the computer without turning the power off. The opposite of hard boot.
soft copy
The version of a document which is stored on a computer disk or similar medium, as opposed to the hard copy which is the paper printout.
soft font
A font that is on the computer's or printer's hard disk, and must be downloaded to the printer before printing.
soft hyphen
A hyphen that will only be set if the word falls at the end of a line which is too long, and has to be broken. Contrast hard hyphen.
soft page break
A page break automatically created by a word processing or report program
after the page reaches a certain length. The user can control the standard page length.
SoftPC
PC emulation software from Insignia Solutions, Inc. SoftPC enables Macintosh and UNIX workstations to run DOS and Windows programs.
software
Software is the computer program that tells a computer's hardware what to do. System software is the operating system that controls the basic functioning capabilities of the computer, network software enables multiple computers to communicate with one another, and language software is used to develop programs. Compare with hardware. See also shareware, freeware.
Software and Intelligent Systems Office
A U.S. Department of Defense (DoD) agency. In 1991, the Information Science and Technology Office (ISTO) was divided into the Software and Intelligent Systems Office and the Computing Systems Technology Office (CSTO).
software audit
A periodic check of computers in an organization to see if all the software installed is licensed.
software bloat
A condition where software, through adding features in successive versions, becomes so elaborate that it takes up too much memory and is too complicated to use.
Software Description Database
A database of software available on the Internet, with short descriptions, which can be accessed via Archie.
software developers kit
(SDK). A set of tools to help programmers write new applications. The kit usually provides tools for creating menus, icons, dialog boxes, etc., and for interfacing the application with the operating system(s) it will be used with.
software development kit
(SDK). A set of tools to help programmers write new applications. The kit usually provides tools for creating menus, icons, dialog boxes, etc., and for interfacing the application with the operating system(s) it will be used with.
software failure
A crash or cessation of processing because of a logic error in a program.
software handshake
Handshaking signals between two computers which are carried by way of extra characters inserted into the data stream; for example, Control-Q (ASCII character 17) for start and Control-S (ASCII character 19) for stop. A hardware handshake communicates the same information by voltage levels or pulses on wires. Computers use handshaking signals to indicate to each other when to start or stop sending data.
software house
A company that creates custom software for specific clients.
software license
A license issued to a person or company who buys a computer program, by the publisher, stating under what conditions the software may be used. Most licenses specify that the user may create a backup for personal use, but only one copy of the software may be used on one machine at a time. Site licenses allow unlimited copying of software within an organization, and charge for the extra use.
software package
An application program or group of programs developed for the general public. Rather than being custom designed for a specific user or company, the software is designed to meet the needs of a variety of users.
software piracy
The illegal copying of software for personal or commercial use.
software pirate
A person or company who makes illegal copies of software for personal or commercial use.
software publisher
A company that develops and markets software for public use.
Software Publishers Association
(SPA). A Washington, D.C. trade organization that supports enforcement of software copyrights.
software suite
A collection of programs sold together as one package. For example, an office software suite might include a word processor, a spreadsheet, a presentation program, and a database program. Some software suites are Lotus SmartSuite, Novell PerfectOffice, and ClarisWorks. Some advantages of buying software as a suite: It costs less to buy the software as a suite than to buy each program separately; the programs in a suite have a similar look and way of operating, making them easier to learn; programs in a suite are compatible for exchanging data and interacting with each other.
software theft
The unauthorized copying of software for personal or commercial use.
software tool
A program used for developing, compiling, or debugging other software.
SoftWindows
Software from Insignia Solutions that allows PowerPC and UNIX to emulate Windows applications.
SOH
Start Of Header. ASCII character 1: Control-A.
SOHO
Small-Office / Home-Office. An acronym referring to small businesses and home-based businesses as a market segment.
Solaris
A UNIX-based operating system and window system for Sun SPARC computers, formerly called SunOS. It includes the Open Look and Motif graphical user interfaces, OpenWindows (the Sun version of X Windows),
DOS and Windows emulation, and ONC networking. It is often used for server operating systems.
solid state
Using solid materials, and the electric and magnetic effects within them, rather than mechanical operation; semiconductors, integrated circuits, and transistors are solid state components.
solid state component
A component which operates through the control of electric or magnetic activity in solids; for example, a crystal diode or a semiconductor.
solid state computer
A computer that uses solid state components, such as semiconductors, rather than electron tubes. The use of solid state components began with second-generation computers.
SONET
Synchronous Optical Network. An ANSI standard for broadband public networks using fiber optics, initiated by the regional Bell operating companies (RBOCs). SONET makes it possible for telecommunications products from different vendors to communicate over networks, with data transmission rates from 51.84 Mbps to 48 Gbps.
sort
To organize information in the desired order. Some computer programs, for example, database and word processing programs, have sort functions which can organize items alphabetically, numerically, or by date, in ascending or descending order.
SOTS
Slap On The Side. External hardware attached to a computer to add memory, expansion slots, etc.
Sound Blaster
Popular PC sound cards from Creative Labs, Inc., Milpitas, CA.
sound board
A plug-in circuit board that enables a computer to record and play back sound. Sound boards may include a MIDI interface, a CD-ROM drive controller, and an audio amplifier for speakers.
sound card
An add-on expansion board that improves a computer's sound quality, and adds other sound capabilities. A sound card makes it possible to use speakers, a stereo, and a microphone to record and play sound; some sound cards also include MIDI.
sound player
A browser helper application that plays sound files, such as RealAudio or SoundMachine.
source code
A computer program written by a programmer in a source language. Source code is input to a compiler or assembler, in order to derive object code (machine code).
source computer
1. The computer in which a program is assembled or compiled for use by another computer (called the target computer). 2. The computer that originates a transmission.
source data
Original data which is input into a computer by the user or which comes from a source program.
source directory
The directory from which data is read.
source disk
The disk from which data is read.
source diskette
The diskette from which data is read.
source drive
A drive from which data is read.
source language
The language a source program is written in, and from which object language is translated.
source program
A program in the original language as written by the programmer, which must be translated into a machine-language object program for the computer to run it.
source route
An address for electronic mail in which the route for the message to take is defined at its source, and listed as a hierarchy of hostnames; for example: abc!def!ghi!jkl or abc%def%[email protected] Usually routing of a message is determined at each stage along the way, based on current traffic on the network.
SPA
Software Publishers Association. A Washington, D.C. trade organization that supports enforcement of software copyrights.
space
1. ASCII character 32: the space character. 2. A 0 bit (a 1 bit is called a mark).
space bar
The long bar on the keyboard, which, when pressed, enters ASCII character 32: a blank space. It is usually pressed with one of the thumbs.
Spacewar
A space-combat simulation game originated in the 1960s, using imagery from E.E. Smith's Lensman science-fiction books.
SPAG
Standards Promotion and Application Group. A group of European OSI manufacturers which publishes the Guide to the Use of Standards (GUS).
spaghetti code
A computer program written in a disorganized and confusing way, using a lot of GO TO statements; following a tangled path like a plateful of spaghetti.
spam
The electronic equivalent of junk mail. See spamming.
spamdex
To stuff a web page full of words in the hope of making it high on the list for search engine robots. Sometimes a web page will have a list of many words, or the same word repeated many times, with the text in the same color as the background. Spamdexing will cause a web page to be kicked from search engine indexes.
spamdexing
Stuffing a web page full of words in the hope of making it high on the list for search engine robots. Sometimes a web page will have a list of many words, or the same word repeated many times, with the text in the same color as the background. Spamdexing will cause a web page to be kicked from search engine indexes.
spamming
The practice of sending copies of a message to many different newsgroups, with no regard to whether the subject matter is appropriate; or sending the same message by email to large numbers of people indiscriminately. Sometimes spams are advertisements. Spamming is considered bad netiquette and very unethical because it not only wastes everyone's time, but also costs money. The sender of the messages does not pay the cost; it is paid by the sites of the recipient and others on the route. Spamming often results in angry email replies from the targeted recipients.
spanned record
A set of related data which spans more than one block.
SPARC International, Inc.<SUP>&
The organization that licenses the SPARC® microprocessors; they also issue a newsletter and provide the public with information on the compatibility of SPARC® machines.
"SPARC® is a registered trademark of SPARC International, Inc. in the U.S. and other countries."
SPARC<SUP>&#174;</SUP>
Scalable Processor Architecture. A high-speed RISC microprocessor developed by Sun Microsystems. It is used in Sun workstations, and has been adopted by some other computer manufacturers.
"SPARC® is a registered trademark of SPARC International, Inc. in the U.S. and other countries."
SPARCstation<SUP>&#174;</SU
A group of workstations from Sun Microsystems that have SPARC® high-speed microprocessors.
"SPARC® is a registered trademark of SPARC International, Inc. in the U.S. and other countries."
sparse array
An array in which most of the elements are zero.
sparse file
A file that has empty spaces where data can be entered in the future.
sparse matrix
A matrix in which most of the elements are zero.
sparse vector
A vector in which most of the elements are zero.
spatial data
Data in the form of two- or three-dimensional images.
SPDL
Standard Page Description Language. An Open Document Architecture standard for a page description language, used to indicate how a document will be printed or displayed.
SPEC
Standard Performance Evaluation Corporation. A California nonprofit organization that maintains standardized performance tests, called benchmarks, for computers; developers of the SPECmark suite of benchmarks.
SPEC CFP92
A series of 14 test programs from SPEC, used to measure the floating point computation of a computer.
SPEC CINT92
A suite of six benchmarks from SPEC, which can be used to test a computer's performance of integer computations.
SPEC rate
A Standard Performance Evaluation Corporation (SPEC) benchmark result that is used to measure throughput of more than one copy of a test in a given time; useful for testing multiprocessor systems. SPEC rate is measured in comparison to the VAX 11/780.
SPEC ratio
The ratio of a computer's speed in performing a SPEC benchmark to the speed of a VAX 11/780 performing the same test.
SPECfp
Standard Performance Evaluation Corporation (SPEC) benchmark for floating point computation.
Special Interest Group
(SIG). A subdivision of a computer user group or other organization that meets to share information about an area of special interest. For example, SIGGRAPH is the special interest group of the Association of Computing Machinery that addresses computer graphics.
special-purpose computer
A computer designed for one specific use. Most computers are general-purpose computers, and can be programmed to do many different kinds of jobs.
specific markup
Adding commands in the text of a document which give specific instructions for formatting, such as type size, type style, center or justify type, etc., as opposed to generic markup which only defines general document elements.
SPECint
Standard Performance Evaluation Corporation (SPEC) benchmark for integer computation.
SPECmark
A suite of 10 benchmarks from Standard Performance Evaluation Corporation (SPEC) that test a computer's integer and floating point computation. One SPECmark is comparable to the performance of a VAX-11/780.
SPECmark89
A 1989 version of SPECmark, now superseded by CINT92 and CFP92.
specs
Specifications; detailed, usually written, plans for something. This term denotes, among other things, the specifications for styling a printed page (fonts, leading, type size and style, etc.), and the specifications for the components of a computer system.
Speech Application Programming Interface
(SAPI). An application programming interface from Microsoft that enables speech synthesis and speech recognition programs to communicate with the Windows 95 operating system.
speech recognition
The ability of a computer to recognize spoken words. Speech recognition can be used to dictate text or to give commands to the computer, and is helpful for people who are unable to type. The way it works is that spoken words are converted into digital data and matched to words already in the computer's dictionary.
Speech Recognition Application Program I
(SRAPI). An application programming interface from Novell, Inc., that facilitates speech recognition with WordPerfect 7.0 and Perfect Office 7.0.
speech synthesis
The generation of speech by a machine, from text input. Speech synthesis is used to enable blind users to read text. Synthesized speech is not hard to recognize, because it lacks normal spoken inflection.
speed buffering
Using a buffer area to make up for differences in speed between input and output. Data received into the buffer is output at the appropriate speed.
speedometer
A device that measures the speed of execution of a computer, usually represented as an LED display.
spelling checker
A computer program that checks the spelling of a document by comparing all the words to the words in its dictionary. The user can add words to the dictionary.
spelling flame
A newsgroup posting that corrects the spelling of a previous posting as a way of making the implication that the previous posting and its writer are ignorant.
Sperry Corporation
A company important in the history of computing. In 1910, Sperry Gyroscope Company was founded to manufacture and sell navigational equipment. Sperry Corporation was formed in 1933. In 1955, Sperry merged with Remington Rand to form Sperry Rand. In 1960, Sperry introduced its 1100 series computer. The 1108, which appeared in 1965, was the first multiprocessor computer. In 1976, Sperry introduced the first cache memory disk subsystem. In 1986, Sperry introduced its 2200 series, forerunner of the ClearPath HMP IX system. Sperry merged with Burroughs the same year to form Unisys Corporation.
SPID
Service Profile Identifier. A number that identifies a user's equipment for connecting to an ISDN (Integrated Services Digital Network) line.
spider
A program that searches the World Wide Web automatically by retrieving a document and all documents linked to it.
spike
A sudden pulse of extra voltage, lasting a fraction of a second, which can cause the computer to crash and damage files or computer components if there is no surge protector on the line. A burst of extra voltage that lasts longer, perhaps several seconds, is called a surge.
Spin Doctor
A challenging computer game in which the player must navigate through an obstacle course of various moving and spinning objects, mostly combinations of balls and sticks, with increasing levels of difficulty.
spin the Web
1. Slang term for browsing the World Wide Web. 2. Participate in creation of the World Wide Web network and its diverse resources.
spindle
The rotating shaft that turns a disk in a drive.
splash screen
On the Macintosh, an introductory screen that appears when opening a program; it usually contains a logo, author credits and copyrights, and contact information for the software company.
spline
A smooth curve that connects a set of points.
split screen
Displaying two or more independent areas of data on screen at the same time. The split screen may be used to have two or more separate files open in the same program or different programs; or it may be used to view different sections of the same file, as in a database or spreadsheet. For example, a spreadsheet may be too wide to see all the columns at one time; a split screen can be used to show a right-hand column at the same time as columns from the left side of the document. Each area of a split screen can be controlled independently.
spoofer
A program used by a cracker to trick a computer system into thinking it is being accessed by an authorized user.
spool
Simultaneous Peripheral Operation On-Line. To perform a peripheral operation while the computer is busy with other work. The most common use of spooling is with the printer; files are sent to the print spooler, which organizes a queue and then prints one file after another.
spool file
A file used to temporarily store data for later processing.
spooler
Software or hardware used to temporarily store data and process it later; for example, a print spooler which stores files to be printed when the printer is available.
spooling
Storing certain input or output on disk for low-speed processing while allowing the computer to continue its normal operations. Spooling is used for printers, plotters, sending email, and other peripheral operations. For example, a file to be printed is sent to the print spooler to wait its turn in the print queue until the printer is ready. Transferring data to the spooler is much faster than printing. While waiting for the file to print, the user can continue to input data, edit files, create new files, etc.
spreadsheet
A table which displays numbers in rows and columns, used for accounting, budgeting, financial analysis, scientific applications, and other work with figures. Originally, paper spreadsheets were used; the computerized versions have the advantage of being able to perform automatic calculations on changing data. Each location in a spreadsheet is called a cell, and each cell has a number, such as A3, B4, etc. The value of a cell may be calculated from a formula involving other cells; for example, C5 may be the sum of A5 and B5. If the data entered in A5 changes, then C5 would be automatically recalculated by the program. This feature makes it possible to use a spreadsheet to project the results of a change in one or more factors. References between cells may be designated as absolute or relative; an absolute reference refers to a specific cell, and a relative reference describes a cell in its relation to the current cell (as two rows above, two columns to the left, etc.). The data within a cell may be a label, a number, or a formula, and may be copied to other cells. There are two- and three-dimensional spreadsheets. The first commercially available spreadsheet program was VisiCalc for Apple II; now there are spreadsheet programs from Microsoft, Borland, Lotus, and many other companies. Microsoft Excel and Lotus 1-2-3 are popular examples.
spreadsheet program
A program which displays a table of numbers in rows and columns, used for accounting, budgeting, financial analysis, scientific applications, and other work with figures. Originally, paper spreadsheets were used; the computerized versions have the advantage of being able to perform automatic calculations on changing data. Each location in a spreadsheet is called a cell, and each cell has a number, such as A3, B4, etc. The value of a cell may be calculated from a formula involving other cells; for example, C5 may be the sum of A5 and B5. If the data entered in A5 changes, then C5 would be automatically recalculated by the program. This feature makes it possible to use a spreadsheet to project the results of a change in one or more factors. References between cells may be designated as absolute or relative; an absolute reference refers to a specific cell, and a relative reference describes a cell in its relation to the current cell (as two rows above, two columns to the left, etc.). The data within a cell may be a label, a number, or a formula, and may be copied to other cells. There are two- and three-dimensional spreadsheets. The first commercially available spreadsheet program was VisiCalc for Apple II; now there are spreadsheet programs from Microsoft, Borland, Lotus, and many other companies. Microsoft Excel and Lotus 1-2-3 are popular examples.
Spring Cleaning
A Mac program from Aladdin used to clean up a hard disk by eliminating duplicate files, uninstalling old applications, and cleaning the preferences folder of old, useless files.
Sprintnet
A public network whose users have access to online services such as CompuServe, Delphi, Portal, and GEnie.
sprite
A small graphic image on the computer screen, that can be moved around independently with a mouse or with keyboard commands. Examples are the ordinary cursor in its many forms, and the characters in video games.
SPS
Standby Power System. An offline backup power supply system which automatically switches on in case of power failure.
spt
Sectors Per Track. Disk storage is organized in sectors, which are pie-shaped slices, and tracks, which are concentric rings. A combination of two or more sectors on a single track makes a cluster or block, the minimum unit used to store information. The number of sectors per track determines the size of each cluster. The number of clusters on a disk's surface determines the storage capacity of the disk. The number of sectors per track is also related to the speed at which a disk is read and the pattern of sector mapping.
SPX
Sequenced Packet Exchange. A Novell NetWare communications protocol used to transmit messages reliably over a network.
spyware
Software that sends information about your Internet sessions back to the computer from which it’s launched. Spyware is often built into free downloads and works in the background without a user’s knowledge. Since it doesn’t record an individual’s personal information, it’s often used to create marketing profiles based on surfing habits.
SQL
Structured Query Language (pronounced SQL or Sequel). A language used to create, maintain, and query relational databases. It is an ISO and ANSI standard. SQL uses regular English words for many of its commands, which makes it easy to use. It is often embedded within other programming languages.
SQL Module Language
Structured Query Language Module Language. An ANSI standard programming language which can be used to interface other programming languages with SQL database management systems.
SQL Server
Structured Query Language Server. A client/server relational database management system from Sybase, Inc. for Windows NT, OS/2, UNIX, VAX, and NetWare servers.
square tape
Magnetic tape in rectangular cartridges instead of on round reels. Quarter-inch cartridges for personal computers and magnetic tape cartridges for mainframe computers are both in this format.
Squeak
A programming language used to communicate with the computer mouse.
SRAM
Static Random Access Memory. A kind of random access memory that requires a constant supply of power in order to hold its content, but does not require refresh circuitry as dynamic random access memory (DRAM) does. Each static RAM bit is a flip-flop circuit made of cross-coupled inverters; the activation of transistors controls the flow of current from one side to the other. Unlike read-only memory (ROM), SRAM will lose its content when the power is switched off. Static RAM is usually faster than dynamic RAM, but takes up more space and uses more power. It is used for the parts of a computer that require highest speed, such as cache memory.
SRAPI
Speech Recognition Application Program Interface. An application programming interface from Novell, Inc., that enables the speech recognition features of WordPerfect 7.0 and Perfect Office 7.0 to communicate with the computer’s operating system.
SS
Single Sided. Refers to a floppy disk that can only store data on one side.
SSBA
Suite Synthetique des Benchmarks de l'AFUU. An AFUU (French Association of Unix Users) public domain benchmark suite.
SSCP
System Services Control Point. Software that manages all resources in a mainframe-based Systems Network Architecture (SNA) network.
SSDD
1. Single Sided Double Density. An old floppy disk format that had data stored only on one side. Double-density meant twice the storage space of the older single density format. 2. Same Stuff, Different Day.
SSI
1. Small-Scale Integration. The use of integrated circuits with less than 100 logic gates, as in the early third-generation computers. 2. Server Side Includes. The ability to include files from the server inside an HTML document by placing tags in the HTML file that link to those files. Using server-side includes makes it unnecessary to include multiple copies of the same information in the HTML file, and make it easier to work with frequently-updated information. Server-side includes are available on some HTTP servers.
SSL
Secure Sockets Layer. A protocol from Netscape Communications Corporation, which is designed to provide secure communications on the Internet.
ST connector
A type of connector for fiber-optic cable that uses a bayonet mount and connects one optical fiber. It has been widely used in commercial wiring.
stack
A data structure used to store items which are retrieved in last-in first-out order (LIFO). A stack can be used to keep track of the sequence of subroutines called in a program. Data is entered or retrieved by “pushing” a new item onto the stack or “popping” the top item off the stack.
stack overflow
An error condition that is the result of trying to put additional items onto a stack when there is no room for them. See stack.
stack underflow
An error condition that results from trying to retrieve an item from an empty stack. See stack.
stacking order
The order of a series of overlapping windows, meaning which one is in front (or on top), which one is in back (on the bottom), and the order of the windows in between.
Stallman, Richard M.
(RMS). Founder of the GNU project and Free Software Foundation.
stand-alone modem
An external modem; a modem that is separate from the computer.
stand-alone system
A system that can run programs independently. It may access data from other systems sometimes.
stand-alone workstation
A workstation that can do its own processing independent of a server or host system.
standard
An agreed-upon set of specifications for hardware or software. Agreeing upon standards makes it possible for different manufacturers to create products that are compatible with each other. Standards may be set by official standards organizations, or they may be unofficial standards that are established by common use.
Standard for Robot Exclusion
World Wide Web Robots (which are also called spiders or wanderers) are programs that traverse many pages in the World Wide Web searching for information. There have been occasions where robots have visited web servers where they were not wanted for one reason or another. Some robots overwhelmed servers with rapid-fire requests, or requested the same files again and again. Another problem was robots visiting parts of web servers that were not appropriate, such as very deep virtual trees, duplicated or temporary information, or cgi scripts that had side effects such as voting. The need became evident for established mechanisms that would allow web servers to tell robots which parts of their server not to access. The Standard for Robot Exclusion is a way robot authors can cooperate to protect web servers against unwanted accesses by robots.
Standard Generalized Markup Language
(SGML). A generic markup language for document formats. SGML makes possible different presentations of the same information by defining the general structure and elements of a document. HTML (Hypertext Markup Language) is based on SGML.
standard input/output
The default input and output channels for a UNIX operating system. Standard input comes from the terminal or keyboard, and standard output goes to the terminal. Either can be redirected to a file or other process.
Standard MIDI File
(SMF). A MIDI file created using the General MIDI Standard.
Standard Page Description Language
(SPDL). An Open Document Architecture standard for a page description language, used to indicate how a document will be printed or displayed.
Standard Performance Evaluation Corporat
(SPEC). A California nonprofit organization that maintains standardized performance tests, called benchmarks, for computers; developers of the SPECmark suite of benchmarks.
Standards Promotion and Application Grou
(SPAG). A group of European OSI manufacturers which publishes the Guide to the Use of Standards (GUS).
Standby Power System
(SPS). An offline backup power supply system which automatically switches on in case of power failure.
Star
The first computer with a graphical user interface, made by Xerox but never successfully commercialized. It was the inspiration for the Apple Macintosh computers, X Windows, Sun workstations, and later Xerox computers.
star network
A network configuration in which each node is connected to a separate line, and all lines lead to the same central hub. From the central station any line can be connected to any other line. An example is a PBX (private branch exchange).
StarBurst
A database management system (DBMS) from IBM.
start bit
A bit which is sent to signal the beginning of a data transmission on a serial line.
start of header
(SOH). ASCII character 1: Control-A.
start of text
(STX). ASCII character 2: Control-B.
start/stop transmission
A way of transmitting data in which one character is sent at a time, and there may be uneven amounts of time between characters. A start bit and a stop bit notify the receiving computer when the transmission begins and ends. This is also called asynchronous transmission. It is different from synchronous transmission, in which strings of multiple characters are transmitted, and the sending and receiving of characters are controlled by timing signals.
startup disk
The disk that is used to start up the computer, also called a boot disk. The startup disk can be a floppy disk or hard disk, but must have the necessary information on it for booting the computer.
startup folder
In Windows 95, a folder containing programs that will automatically execute when Windows starts up.
Startup Items
A folder in Macintosh System 7; any files placed in this folder will open when the computer is started. For example, a startup screen, a sound file to be played when the computer first starts, a reminder calendar, or application programs can be startup items. Normally, an alias of a file is placed in this folder rather than the file itself.
startup movie
A movie clip that is set up to play automatically when the computer first starts up. The user can choose the movie clip.
startup screen
A screen that is automatically displayed when the computer starts up. It may have text or images, and can be programmed by the user.
startup volume
The disk that is used to start up the computer, also called a startup disk. The startup volume can be a floppy disk or hard disk, but must have enough of the computer’s operating system on it to start the computer.
STARTUP.CMD
(Startup Command). In the OS/2 system, a file that is executed when the computer is started.
state-of-the-art
Incorporating the newest and most advanced technology.
statement
An instruction in a high-level programming language, which may be translated into one or more machine code instructions by the computer.
static electricity
An isolated and nonmoving electric charge, such as is produced by friction in a low-humidity environment. The charge may be intentionally generated, as in an electrostatic printer.
Static IP Address
A static or dedicated IP Address is a type of account from an ISP where your computer(s) are assigned the same IP Address at all times. While this used to be a requirement for web-site serving, it is usually used today for security purposes.
static random access memory
(SRAM). A kind of random access memory that requires a constant supply of power in order to hold its content, but does not require refresh circuitry as dynamic random access memory (DRAM) does. Each static RAM bit is a flip-flop circuit made of cross-coupled inverters; the activation of transistors controls the flow of current from one side to the other. Unlike read-only memory (ROM), SRAM will lose its content when the power is switched off. Static RAM is usually faster than dynamic RAM, but takes up more space and uses more power. It is used for the parts of a computer that require highest speed, such as cache memory.
station
One of the nodes in a network.
status bar
A bar along the bottom of a window where information is displayed about the current application. It may tell the position of the cursor on the screen, the current date and time, the page number, etc. The information shown in the status bar changes with different programs and different commands.
status light
A little light on a computer or peripheral, usually an LED, which indicates the device is on, a drive is being accessed, or other information about the operating status. Modems have a row of lights that give information about the status of transmission.
status line
A strip along the bottom of a window where information is displayed about the current application. It may tell the position of the cursor on the screen, the current date and time, the page number, etc. The information shown in the status line changes with different programs and different commands.
STB
Set-Top Box. A box that sits on top of a television set and is the interface between the home television and the cable TV company. New technologies evolving for set-top boxes are video-on-demand, video games, educational services, database searches, and home shopping.
STD
Standard; refers to a set of documents (STD 1, STD 2, etc.) that define Internet standards.
STD 1
Standard 1. The official list of Internet standards defined by the Internet Architecture Board (IAB).
STD 15
Standard 15. A document which defines standards for Simple Network Management Protocol (SNMP).
STD 2
Standard 2. A document that lists current Internet Assigned Numbers.
STD 9
Standard 9. The document that defines standards for File Transfer Protocol (FTP).
stderr
Standard error. A UNIX designation. Like standard output, standard error also normally is sent to the terminal.
stdin
Standard input. The default input channel for a UNIX operating system, which is normally from the terminal or keyboard, but can be redirected to come from a file or connected by piping to another process.
stdio
Standard I/O (standard input/output). The default input and output channels for a UNIX operating system. Standard input comes from the terminal or keyboard, and standard output goes to the terminal. Either can be redirected to a file or other process.
stdout
Standard output. The default output channel for a UNIX operating system, which normally goes to the terminal, but can be redirected to go to a file or connected by a pipe to another process.
STDWIN
A graphical user interface with windows from CWI, available for Macintosh and X Windows.
stealth virus
A virus that has ways of hiding itself so it is hard to detect.
stepwise refinement
A way of developing a computer program by first describing general functions, then breaking each function down into details which are refined in successive steps until the whole program is fully defined. Also called top-down design.
stereogram
A two-dimensional image which seems to be three-dimensional if viewed a certain way (at a certain distance, focus, and angle).
stickiness
A measure of how long the average user spends at a website. In contrast to measuring hits, this measure provides an indication of how interesting the website itself is, rather than just how interesting the ad or link is that brings users to the site.
sticky menu
A menu that will stay open if the pointer is put in the correct position, which is sometimes to the left of it and sometimes to the right.
stiffy
Another name for the 3.5" floppy disk, which refers to the stiffness of the jacket compared to the more flexible 5.25" floppy.
STIK
Shirt, Tie, Keyboard. Computer slang for a boring corporate IS person; similar to ÒsuitÓ.
still frame
A single frame from a video, film, or CD-ROM, which shows a still picture.
stomp on
To overwrite by accident.
Stone Age
In computer jargon, the early period of first-generation computers.
stop bit
A bit which signals the end of a unit of transmission on a serial line. A stop bit may be transmitted after the end of each byte or character.
stoppage
A condition of being damaged to the point of unusability.
storage
A device into which data can be placed, held, and later retrieved. “Main storage” refers to the computer's memory, the space used for executing instructions; “auxiliary storage” refers to disks, diskettes, magnetic tape, and other media for holding data.
Storage Area Network (SAN)
A high-speed network that connects multiple storage devices so that they may be accessed on all servers in a Local Area Network (LAN) or Wide Area Network (WAN).
storage capacity
The amount of data a storage medium can hold; usually expressed in kilobytes, megabytes, or gigabytes.
storage device
A peripheral device for storing data. Tapes and disks are storage devices.
storage dump
A printout of whatever is in system storage at the time.
storage management services
(SMS). Software that can be used to back up data on a network by routing it to designated storage locations.
storage media
Any media used for storing data, such as hard disks, floppy disks, optical disks, or magnetic tape.
store
To copy or transfer data from the computer to a storage medium such as disk or tape.
store-and-forward routing
A way of transmitting messages in which each station along the path must receive the whole message before it can forward any of it to the next station. See wormhole routing.
STP
Shielded Twisted Pair. Twisted pair cable that is wrapped in a metal sheath to provide extra protection from external interfering signals.
Stratus Computer, Inc.
A computer manufacturer in Marlboro, Massachusetts, that makes the XA/R and XA/2000 computers.
streaming
Playing audio or video immediately as it is downloaded from the Internet, rather than storing it in a file on the receiving computer first. Streaming is accomplished by way of web browser plug-ins, which decompress and play the file in real time; a fast computer and fast connection are necessary.
streaming MP3
A technology that allows the user to listen to MP3s as they are downloading, rather than downloading a whole MP3 and then listening to it.
strikethrough
Letters that have a line through them as though they have been crossed out; sometimes used in advertising.
String Oriented Symbolic Language
(SNOBOL). A programming language from Bell Labs used for string processing, compiler development, and pattern matching.
STROBES
Shared Time Repair of Big Electronic Systems. A programming language used in testing computers.
stroke weight
The light, medium, or bold appearance of a typeface.
Structured Query Language
SQL (pronounced SQL or Sequel). A language used to create, maintain, and query relational databases. It is an ISO and ANSI standard. SQL uses regular English words for many of its commands, which makes it easy to use. It is often embedded within other programming languages.
strudel
ASCII character 64: @ . Also called the commercial at sign.
stub network
A network that carries packets to and from local hosts.
The decompression program for the MacintoshStuffit compression utility.
STX
Start Of Text. ASCII character 2: Control-B.
subclass
In object-oriented programming, a class, or object type, which inherits attributes and methods from another class (called a superclass).
subdirectory
A directory that is inside, or subordinate to, another directory. A subdirectory must be reached by going through all directories above it.
subfolder
A folder that is inside, and subordinate to, another folder.
subject line
In an electronic mail program, the short line of type that indicates what the message is about. Using a well-chosen subject line will help both the sender and receiver identify the subject of the message at a glance, without having to open and read it. Some email filtering programs can filter mail by subject line, so that all mail on a certain subject is filed, given high priority, or thrown out.
subnet
1. A part of a network, which has the same network address as other parts of the network but a unique subnet number; a subdivisional network interconnected and situated within a larger network. 2. Within the ISO/OSI reference model, the layers below the transport layer are referred to as the subnet. They consist of the network, data link, and physical layers.
subnet mask
A number used to identify a subnetwork when an IP address is shared by multiple networks.
subnotebook
A portable computer that weighs from two to six pounds. The subnotebook is smaller and lighter than a notebook computer, and has less storage space and a smaller screen.
subscript
Subscript characters are below the line of regular text and often smaller. Subscripts are used for chemical symbols (H2O) and mathematical formulae.
subset
A set that is included in another set, which is called a superset. The superset has all the characteristics of the subset and additional characteristics.
substitution cipher
A way of enciphering a message by replacing letters with other letters.
suffix notation
The same as reverse Polish notation. A way of expressing a sequence of calculations without using parentheses to show which operation must be performed first. For example, the expression 2(4+5), which instructs the reader to add 4 + 5 and multiply by 2, would be written 2 4 5 + * in suffix notation. To make the calculation, read from left to right until you find an operation, then perform the operation on the numbers immediately to the left of it, and continue to the next operation. So 2 4 5 + * becomes 2 9 * and then 18. See also Polish notation.
SUG
Sun User Group.
suit
An administrative or management person; someone who wears suits. Generally a term used by hackers and other non-suits.
Suite Synthetique des Benchmarks de l�
(SSBA). An AFUU (French Association of Unix Users) public domain benchmark suite.
Sun Microsystems, Inc.
One of the biggest U.S. computer manufacturers, based in Mountain View, California, founded in 1982. Sun is known for producing high-performance workstations, the Open Network Computing and Network File System software, and a version of UNIX called Solaris (formerly SunOS). Sun 2 and 3 workstations used Motorola 680×0 microprocessors; Sun 4 uses SPARC.
SunConnect
The division of Sun Microsystems that develops networks.
SunExpress
The division of Sun Microsystems responsible for distribution.
SunOS
A version of UNIX created for Sun workstations, later replaced by Solaris.
SunPics
The division of Sun Microsystems involved with printing and imaging.
SunPro
The division of Sun Microsystems that produces programming tools.
SunScan
Free Year 2000 compliance software from Sun Microsystems that scans Sun's hardware, operating environment, and software products and provides patches if needed.
SunSoft
The division of Sun Microsystems that produces system software.
SunView
A windows system from Sun Microsystems.
super 7
A socket similar to socket 7, but with better performance; the super 7 can handle a bus speed of 100 MHz.
super high frequency
(SHF). Electromagnetic frequencies in the range of 3 to 30 gigaherz.
Super VHS
SVHS (Super Video Home System). A high-quality video format that has higher resolution than normal VHS. It must be played on a videocassette recorder that supports the SVHS format, and to see the sharper image resulting from the higher resolution, it must be played on a high-resolution television set.
Super Video Graphics Array
(SVGA). A video display standard for color monitors, defined by VESA. SVGA monitors display up to 16.7 million colors with resolutions up to 1,280 x 1,024 pixels, and are good for multimedia applications.
Super-JANET
A further development of JANET, the UK educational and research network run by UKERNA. Super-JANET provides network facilities for new applications such as Multimedia Conferencing.
superclass
In object-oriented programming, a class, or object type, from which another class (called a subclass) inherits attributes and methods.
supercomputer
A very fast and powerful computer, outperforming most mainframes, and used for intensive calculation, scientific simulations, animated graphics, and other work that requires sophisticated and high-powered computing. Cray Research and Intel are well-known producers of supercomputers.
superconductor
A material that has almost no resistance to the flow of electricity. Superconductors work at very low temperatures.
SuperJanet
An upgrade of JANET (Joint Academic Network), a national high-speed broadband network created to support higher education and research in the United Kingdom.
superprogrammer
A very fast and effective programmer.
superscript
Superscript characters appear above the line of regular text and are often smaller. Superscripts are used for footnotes and exponents (r2).
superset
A set that includes other sets within it, which are called subsets. For example, a software or hardware upgrade may be a superset of the previous version in that it can do everything the previous version can do and more.
superuser
1. A privileged account with more powers than the ordinary user has on a system. 2. A user who is not a programmer or hacker, but is expert with some aspect of computing.
surf
1. To ride the waves in the ocean. 2. To navigate in cyberspace like a surfer riding the top of a wave.
surfing
By analogy with riding waves in the ocean, traveling from place to place on the Internet. The idea “Internet surfing” may come from “channel surfing” on the television, which means switching from channel to channel looking for something interesting. Recreational use of the Internet is similar.
surge
A sudden pulse of extra voltage, lasting a second or longer, which can cause the computer to crash and damage files or computer components if there is no surge protector on the line. A burst of extra voltage that lasts only a fraction of a second is called a spike.
surge protector
An electrical device that protects a computer from spikes and surges in the power line. All computers have some surge protection built in, but this protection is not always enough. External surge protectors come in the form of a unit that plugs into the wall, with outlets for several electrical plugs. However, not all outlet bars have surge protection.
surge suppressor
An electrical device that protects a computer from spikes and surges in the power line. All computers have some surge suppression built in, but this protection is not always enough. External surge suppressors come in the form of a unit that plugs into the wall, with outlets for several electrical plugs. However, not all outlet bars have surge suppression.
SVC
Switched Virtual Circuit. A network connection that is established from sender to receiver at the time of transmission, as in a switched public network. Contrast with PVC.
SVCD
Super Video CD. In many respects, SVCDs are upgraded versions of VCDs. SVCDs use MPEG as its compression standard and can hold between 35 to 60 minutes of full motion video on 74/80 min CDs. SVCDs can be played in DVD players, DVD-ROM and CD-ROM drives.
SVD
Simultaneous Voice and Data. The multiplexing of voice and data for transmission over an analog telephone line. Examples are MultiTech Supervisory Protocol (MSP) and Radish Communications VoiceView.
SVGA
Super Video Graphics Array. A video display standard for color monitors, defined by VESA. SVGA monitors display up to 16.7 million colors with resolutions up to 1,280 x 1,024 pixels, and are good for multimedia applications.
SVHS
Super VHS (Super Video Home System). A high-quality video format that has higher resolution than normal VHS. It must be played on a videocassette recorder that supports the SVHS format, and to see the sharper image resulting from the higher resolution, it must be played on a high-resolution television set.
swap file
Also called virtual memory. A portion of the hard drive set aside to use when more RAM is needed. Virtual storage is divided into segments called pages; each page is correlated with an address in physical memory. When the address is referenced, the page is swapped into memory; it is sent back to disk when other pages must be called.
switch
1. A communications device that controls the operation and routing of a signal path. 2. A circuit element which enables a device to be turned either on or off. 3. A networking device which can send packets directly to to port associated with a given network address.
Switched Multimegabit Data Service
(SMDS). A high-speed data communications service developed by Bellcore for connecting local area networks over the public telephone lines.
switched network
1. A network in which a temporary connection is established by closing a switch; an example is the ordinary telephone, where connections are made by dialing. 2. A packet-switched network, in which a temporary connection is established between points for transmitting data in the form of packets.
switched virtual circuit
(SVC). A network connection that is established from sender to receiver at the time of transmission, as in a switched public network. Contrast with permanent virtual circuit.
Sybase Corporation
A relational database management system (DBMS) vendor in Emeryville, California.
SyJet
A removable hard drive from SyQuest with over 1 GB storage. It is connected with the computer via a SCSI interface.
Symantec AntiVirus for Macintosh
(SAM). An antivirus program from Symantec Corporation, Cupertino, California.
SymbMath
Symbolic math software for MS-DOS.
Symbol font
A font that has Greek and other special characters useful, among other things, for mathematical formulas.
SYMM
Synchronized Multimedia. Productions that use a combination of synchronized multimedia elements such as audio, video, text, graphic images, and hyperlinks. One example is the broadcasting of television-like content on the World Wide Web. See also SMIL and SYMM-WG.
SYMM-WG
Synchronized Multimedia Working Group. A W3C working group that developed the SMIL 1.0 specification for bringing synchronized multimedia content to the Web. The working group is composed of experts in CD-ROM, interactive television, audio/video streaming, and the World Wide Web, from research organizations and technology companies.
symmetric digital subscriber line
(SDSL). A technology that can send data at up to 3 Mbps over ordinary copper telephone lines. SDSL sends digital pulses in the high-frequency bandwidth not used by normal voice communications, which makes it possible to have voice and data transmissions over the same wires. SDSL is called symmetric because, unlike ADSL (asymmetric digital subscriber line), it has the same data rates for transmission from server to client and from client to server. A special SDSL modem is necessary.
symmetric encryption
A form of cryptography in which sender and receiver have the same key.
symmetric key cryptography
In computer security, cryptography in which both ends have the same encryption key; it uses the same key for encryption and decryption.
symmetric multiprocessing
(SMP). A computer system which has two or more processors connected in the same cabinet, managed by one operating system, sharing the same memory, and having equal access to input/output devices. Application programs may run on any or all processors in the system; assignment of tasks is decided by the operating system. One advantage of SMP systems is scalability; additional processors can be added as needed. However, in an SMP system, if one processor is down, the whole system is down.
symmetric multiprocessor
A parallel processor which performs symmetric multiprocessing.
Symphony
An integrated software package from Lotus, an improvement on the Lotus 1-2-3 spreadsheet. Symphony includes speadsheet, business graphics, word processing, database management, report generation, and communications.
SyncDRAM
Synchronous Dynamic Random Access Memory (SDRAM). High-speed DRAM that adds a separate clock signal to the control signals. SDRAM can transfer bursts of non-contiguous data at 100 MBytes/sec, and has an access time of 8-12 nanoseconds. It comes in 64-bit modules: long 168-pin DIMMs.
synchronized multimedia
(SYMM). Productions that use a combination of synchronized multimedia elements such as audio, video, text, graphic images, and hyperlinks. One example is the broadcasting of television-like content on the World Wide Web. See also SMIL and SYMM-WG.
Synchronized Multimedia Integration Lang
(SMIL). A language developed by the W3C Synchronized Multimedia (SYMM) Working Group, that makes possible the broadcast of television-like content on the Web, and lowers the bandwidth needed for this kind of transmission. SMIL makes the production of audio-visual materials easy; users do not have to learn a programming language and can work with a simple text editor. SMIL uses XML syntax, and makes it possible to combine video, audio, text, graphic images, and hyperlinks.
Synchronized Multimedia Working Group
(SYMM-WG). A W3C working group that developed the SMIL 1.0 specification for bringing synchronized multimedia content to the Web. The working group is composed of experts in CD-ROM, interactive television, audio/video streaming, and the World Wide Web, from research organizations and technology companies.
synchronous
Capable of performing two or more processes at the same time, such as sending and receiving data, using a common timing signal.
Synchronous Data Link Control
(SDLC). A data transfer protocol used in IBM's SNA networks. SDLC conforms to ISO’s High-level Data Link Control (HDLC) and ANSI’s Advanced Data Communication Control Procedures (ADCCP).
synchronous digital subscriber line
(SDSL). A digital subscriber line that sends data at the same speed in both directions. SDSL is intended for business use, whereas ADSL (asynchronous digital subscriber line), in which data downloads much faster than it uploads, is mainly for home use. See also ADSL, DSL, HDSL.
Synchronous DRAM
Synchronous Dynamic Random Access Memory (SDRAM). High-speed DRAM that adds a separate clock signal to the control signals. SDRAM can transfer bursts of non-contiguous data at 100 MBytes/sec, and has an access time of 8-12 nanoseconds. It comes in 64-bit modules: long 168-pin DIMMs.
Synchronous Dynamic Random Access Memory
(SDRAM). High-speed DRAM that adds a separate clock signal to the control signals. SDRAM can transfer bursts of non-contiguous data at 100 MBytes/sec, and has an access time of 8-12 nanoseconds. It comes in 64-bit modules: long 168-pin DIMMs.
synchronous graphic RAM or synchronous g
(SGRAM, Synchronous Graphic Random Access Memory). Memory that is used for graphic-intensive operations such as 3-D rendering and displaying full-motion video.
Synchronous Graphic Random Access Memory
(SGRAM). Memory that is used for graphic-intensive operations such as 3-D rendering and displaying full-motion video.
synchronous key encryption
A method of encryption that uses two interlocking keys, designed so a message encoded using one key can be decoded using the other key. If one key is made public and the other kept private, then anyone who has the public key can send a message that can be decoded using the other key. The sender can add another layer of encryption by also encrypting the message with the sender's private key, so it has to be decoded first with the sender's public key and then with the receiver's private key. This is a powerful encryption method, of which PGP is an example.
Synchronous Optical Network
(SONET). An ANSI standard for broadband public networks using fiber optics, initiated by the regional Bell operating companies (RBOCs). SONET makes it possible for telecommunications products from different vendors to communicate over networks, with data transmission rates from 51.84 Mbps to 48 Gbps.
synchronous transfer mode
This is a proposed transport level technique used in a Broadband Integrated Services Digital Network (B-ISDN). Herein, time-division multiplexing and switching are both used across the user's network interface.
synchronous transmission
A means of sending data in which a clocking signal is used and the characters are separated by time intervals, rather than by start and stop bits as in asynchronous transmission. Synchronous transmission is faster than asynchronous because there is no need for a start bit and stop bit on each character; however, it is more expensive. Most computer terminals use asynchronous data transmission; some modems convert asynchronous signals into synchronous signals for very fast transmission.
SyQuest disk
A cartridge hard disk that is used with the SyQuest removable hard drives. SyQuest disks are available in several 5.25″ formats with up to 200 MB storage, or 3.5″ formats with up to 270 MB. The SyJet, a newer SyQuest drive, has cartridges with over 1 GB storage.
SyQuest drive
A removable hard disk drive which is connected to the computer via a SCSI interface. SyQuest drives, developed by SyQuest Technology, come in 3.5″ and 5.25″ sizes, with removable cartridges that can greatly increase the computer's storage. A newer drive from SyQuest is SyJet, a 1.+GB external SCSI drive.
SyQuest Technology, Inc.
A Fremont, California corporation that developed a line of removable hard disk drives called SyQuest drives, with removable cartridge hard disks.
sys admin
System administrator. The person in charge of a multiuser computer system. The system administrator designs the system and manages its use.
sysop
System operator. The operator of a local area network, bulletin board, or online service. The sysop may act as a mediator for online conferences or forums.
sysprog
Systems programmer. 1. A person who writes system programs, those programs which enable a computer system to function, as opposed to application programs. 2. A technical expert in a large corporation who oversees the computer systems and is responsible for the installation and integration of new hardware and software.
system administrator
The person in charge of a multiuser computer system, also called sys admin. The system administrator designs the system and manages its use.
system analyst
Also called systems analyst. A person who designs or modifies an information system to meet the requirements of its end user. System analysis includes investigating the program's feasibility and cost, producing documentation, and testing a prototype of the system at several stages of its design.
system board
The motherboard; the main printed circuit board that contains the central processing unit for the computer, memory, and sometimes printer ports or other devices.
system clock
The main clock that controls the timing within a computer by generating a series of pulses that are used to synchronize its circuits and operations.
system disk
A disk that contains the operating system, or enough of the operating system to boot the computer. It can be a hard disk, a floppy disk, a SyQuest disk, or a CD-ROM.
system enabler
A system update file for Macintosh that must be present to tell the System 7 operating system which model of Macintosh it is running.
System Folder
A folder on the Macintosh that contains the System, Finder, printer drivers, control panels, fonts, desk accessories, extensions, preferences, INITs, and other files that help to run the computer.
system integration
Assembling many components so they can work together as a system.
system level
On the level of the operating system or system programs.
system management
The management of computer systems in an enterprise, which may involve a system manager and system management software. System management includes analysis and design of systems, development and updating of software, elimination of redundancy, and management of networks, security, job scheduling, maintenance and repair.
system manager
A systems programmer who manages the technical aspects of systems development, which includes software analysis and design, program implementation and maintenance, and updates.
system memory
The memory the operating system uses.
system operator
The operator of a local area network, bulletin board, or online service, also called sysop. The sysop may act as a mediator for online conferences or forums.
system program
A program which is part of the system software used to control the computer and run applications. System programs include database managers, drivers, communications and messaging protocols, the basic input/output system, etc. Contrast with application program.
System Services Control Point
(SSCP). Software that manages all resources in a mainframe-based Systems Network Architecture (SNA) network.
system software
The software which controls the computer and runs applications. System programs include operating systems, database managers, drivers, communications and messaging protocols, basic input/output system, etc.
system time
The time of day according to a clock in the computer, which runs on a battery so it keeps time even when the computer is turned off. The system time is recorded when files are created or edited. The system time is also used for calendar and reminder programs, electronic mail schedules, and various other operations.
system unit
The main unit of a computer, that contains the central processing unit (CPU) and motherboard. It may have disk and diskette drives, ROM, RAM, and one or more input/output channels. Expansion units can be attached to give the computer added capabilities.
Systeme Internationale d'Unites
(SI). The international metric system.
Systems Administrators Guild
(SAGE). A special technical group of the USENIX Association, a body which focuses on research and innovation in UNIX and open systems.
systems analysis
The analysis of an information system with a view to designing or modifying it to meet the needs of the end user. Systems analysis includes investigating a program for feasibility and cost, creating documentation, and testing a prototype of the system at several stages of its design.
systems analysis definition
(SAD). The beginning step of systems analysis, in which the end user's requirements are defined in order to get an idea of what kind of system must be designed to meet those needs.
systems analyst
Also called system analyst. A person who designs or modifies an information system to meet the requirements of its end user. Systems analysis includes investigating the program's feasibility and cost, producing documentation, and testing a prototype of the system at several stages of its design.
Systems Application Architecture
(SAA). A set of interfaces, guidelines, and protocols developed by IBM to encourage the development of software that is consistent regardless of hardware or operating system. SAA governs user interfaces, communications protocols, programming languages, and procedure libraries.
systems development
The analysis and design of computer systems, including the development and implementation of applications.
systems integration
Assembling complete systems out of many components, and integrating them so all work together.
systems integrator
A company that takes components from more than one vendor and assembles complete computer systems for sale.
systems management
The management of computer systems in an enterprise, which may involve a systems manager and systems management software. Systems management includes analysis and design of systems, development and updating of software, elimination of redundancy, and management of networks, security, job scheduling, maintenance and repair.
Systems Network Architecture
(SNA). A networking protocol standard for IBM mainframes and IBM-compatible mainframes.
systems programmer
Abbreviated sysprog. 1. A person who writes system programs, those programs which enable a computer system to function, as opposed to application programs. 2. A technical expert in a large corporation who oversees the computer systems and is responsible for the installation and integration of new hardware and software.
T
(Tera-). Trillion; 10^12. Or, 2^40 (1,099,511,627,776). Binary numbers are often used when measuring computer storage.
T-byte
Terabyte. A trillion (10^12) bytes. Or, 2^40 (1,099,511,627,776) bytes. Binary numbers are often used when measuring computer storage.
T1 carrier
A telephone line connection for digital transmission that can handle 24 voice or data channels at 64 kilobits per second, over two twisted pair wires. T1 lines are used for heavy telephone traffic, or for computer networks linked directly to the Internet.
T1 line
A telephone line connection for digital transmission that can handle 24 voice or data channels at 64 kilobits per second, over two twisted pair wires. T1 lines are used for heavy telephone traffic, or for computer networks linked directly to the Internet. T1 lines are normally used by small and medium-sized companies with heavy network traffic. They can send and receive very large text files, graphics, sounds, and databases very quickly. Sometimes referred to as a leased line, a T1 is too large and expensive for individual home use.
T3 carrier
A connection made up of 28 T1 carriers, used to transmit digital signals on fiber-optic cable at 44.736 megabits per second. T3 can handle 672 voice conversations or one video channel.
T3 line
A connection made up of 28 T1 carriers, used to transmit digital signals on fiber-optic cable at 44.736 megabits per second. T3 can handle 672 voice conversations or one video channel. The T3 line has enough bandwidth to transmit full-motion real-time video, and very large databases over a busy network. A T3 line would be installed as a major networking channel for a large corporation or university with high volume network traffic. The backbones of the major Internet service providers are comprised of T3 lines.
TA
ISDN Terminal Adapter. A device that connects a computer to an ISDN channel. It is used instead of a modem, and is either an external unit or a plug-in adapter card. Some terminal adapters have the ability to automatically switch between analog and digital modes.
tab
To hit the tab key or give another command that advances the cursor to the next tab stop. Tab stops are used for tabular material (material that is arranged in a table) to line up text in columns.
tab character
ASCII character 9: Control-I is the character for a horizontal tab. ASCII character 11: Control-K is the character for a vertical tab. The tab character moves the cursor, and any text in front of it, to the next tab stop. It is normally invisible, but certain keyboard commands such as Show Invisibles or command-J will make the hard returns, spaces, and tabs visible on the screen (though they still will not show up in print). In this case, the tabs look like right-facing arrows.
tab clear
A key on a typewriter that is used to clear tab stops.
tab delimited
Having tabs as separators between data elements. For example, in a database or spreadsheet, the tab key can be used to move from one field or cell to the next. The file is tab-delimited (even though the user also has the option to use the mouse to move around). The data from one of these files can be exported into a tab delimited text file.
tab key
A key near the top left of the computer keyboard that is used to move the cursor to a tab stop, from one field to the next in a database, or from cell to cell in a spreadsheet. In some programs, the tab key pressed with the shift key moves in the opposite direction.
tab settings
Settings used in a document to line up text in columns. The tab key is used to move the cursor from one tab stop to the next. In word processing programs, tab settings can be entered by typing in numbers or by clicking on a ruler.
table
1. A presentation of information organized in rows and columns. spreadsheet and database programs provide the best tools for working with tables. A database can show and work with intricate relationships between and among fields and databases. 2. In programming, same as an array.
www.clearinghouse.net).
The Bread Board System
(TBBS). Software which was used for the early Bulletin Board Systems (BBSs), originally coded under CP/M in the early 1980s to run on the Tandy TRS-80 computers and later recoded to run under DOS.
The Open Trading Protocol
(OTP). A worldwide standard for retail trade on the Internet. The OTP is a set of open standards, freely available to developers and users, built on XML. The OTP standards will create a consistent framework for electronic commerce, which will be easy for consumers to use.
The Web
The World Wide Web (WWW). A hypermedia-based system for browsing Internet sites. It is named the Web because it is made of many sites linked together; users can travel from one site to another by clicking on hyperlinks. Text, graphics, sound, and video can all be accessed with browsers like Mosaic, Netscape, or Internet Explorer. The Web can also be accessed with text-only browsers like Lynx.
the wire
Slang term for the Internet.
Theological Markup Language
(ThML). An XML-based markup language for reading books online, specifically theological texts. ThML was created for the Christian Classics Ethereal Library (CCEL).
therblig
The fundamental motions of the hands of a worker. These operations are made up of 17 types of motion: search, select, grasp, reach, move, hold, release, position, pre-position, inspect, assemble, disassemble, use, unavoidable delay, avoidable delay, plan, and test to overcome fatigue. Frank Bunker Gilbreth defined these motions in his system of motion study. (Therblig is Gilbreth spelled backwards).
thin client
A simple client machine or program that performs very little processing. In this client/server arrangement, most of the application processing is done in the (fat) server. For example, a thin client may supply only the graphical interface. The advantage of a thin client is simpler hardware and simpler maintenance; the maintenance for applications is done on the server.
thin film transistor
(TFT). A component of high-performance active matrix LCDs, in which transistors are built into each pixel within the screen.
thin film transistor LCD
(TFT LCD). LCD (liquid crystal display) technology, used for computer screens, in which there is a transistor for each pixel, which prevents losing image quality between scans. Also called active matrix display.
third generation computer
A computer built using integrated circuits. Third-generation computers had small-scale integration and began to be designed after the mid-1960s. During this time period, minicomputers were developed.
third generation language
A high-level language; designed so people could write programs in language easier to understand than assembly language. Examples of third generation languages are BASIC, COBOL, FORTRAN, PASCAL, and C.
Third Party Mail Relay
Third Party Relay occurs when a mail server processes messages that was not sent or received by a local user. In the past, this technique has been used to debug mail connectivity or to go around mail problems. More recently, Third Party Relay has been abused by spammers as they hijack servers to send out their messages. The e-mail appears to have been sent from the hijacked server, even though the server had only acted as a relay point.
ThML
Theological Markup Language. An XML-based markup language for reading books online, specifically theological texts. ThML was created for the Christian Classics Ethereal Library (CCEL).
Thompson, Ken
The original developer of UNIX, at AT&T; it was later developed further by Dennis Ritchie and others.
Thread
1. A series of messages and replies relating to a topic or theme in an email exchange or Internet newsgroup. 2. In programming, a thread is one part of a larger program that can be executed independent of the whole.
thread sled
A World Wide Web browser, or software used for chat or newsgroup messaging.
threaded Internet newsreader
(tin). A newsreader for an Internet newsgroup.
ThreadMark
A popular benchmark made by Adaptec.
Three Tunes
A HyperCard virus that plays three German folk tunes and displays the messages “Hey, what are you doing?” and “Don’t panic.” This virus can cause a system crash.
three-dimensional sound
(3D sound). Sound that seems to come from various directions, creating the effect of a three-dimensional space. 3D sound is used in virtual reality; this effect can be obtained with stereo headphones.
throughput
In computer technology, throughput is the amount of work that a computer can do in a given time period. In data transmission, throughput is the amount of data moved successfully from one place to another in a given time period.
Thumbnail
A miniature dislay of a image or page. Thumbnails are used to allow for fast browsing though multiple images. Clicking on a thumbnail will usually allow the complete image to be viewed on the screen.
THz
Terahertz. One trillion cycles per second.
TI
Texas Instruments. A Dallas, Texas manufacturer of personal computers, semiconductors, and calculators.
TIFF
Tagged Image File Format. A bitmap graphics file format that was developed by Aldus and Microsoft for storing scanned images. It can be used with black and white, gray scale, 8-bit color, and 24-bit color images, and transfers well between different platforms. TIFF images can be compressed using LZW compression or other compression formats.
tilde
ASCII character 126: ~ tilde. Used in some cases to represent a user's home directory. World Wide Web home pages often use the tilde in this form: www.some.com/~jones.
TIM
Telecommunications Interchange Markup (also called Technical Information Markup). An SGML-based markup for communicating information related to telecommunications.
time bomb
A kind of logic bomb that is triggered either on a particular date, or according to the length of time the system or program containing it is in use. It may be triggered once or periodically.
time division multiple access
(TDMA). A multiplexing technology used with satellites and cellular phones, in which multiple channels of data are interleaved (each signal is assigned to a different time interval, and the signals are transmitted by taking turns).
time division multiplexing
(TDM). A multiplexing technique (a way of transmitting two or more signals at the same time over the same communications channel) in which the individual signals are combined by interleaving bits.
time sharing
A computer environment that allows multiple users to work independently at the same time, usually from separate terminals. Time sharing resembles multitasking (one user, many tasks) in that the processor takes turns between the different tasks, giving each task a tiny amount of time, so that it appears the different tasks are running at the same time.
time-sharing
Allowing multiple users to work independently at the same time, usually from separate terminals. Mainframes and minicomputers are usually time-sharing computers.
tin
(threaded Internet newsreader). A newsreader for an Internet newsgroup.
TinyFugue
(TF). A popular UNIX and OS/2 client for MUSH and MUD games.
TM
Test Mode. A modem status signal indicated by a light on the modem, which means the modem is in test mode.
TN
Telnet. A terminal emulation protocol that lets a user log in remotely to other computers on the Internet; it has a command line interface. Originally developed for ARPAnet, Telnet runs on top of the TCP/IP protocol.
Toadie
A virus that first became a problem on the Internet in August 1999. Toadie is a rapid infector that infects a large number of executable files each time it is run. It slows down the infected computer each time it propagates. It also encrypts infected files and corrupts any infected file that is subsequently edited.
token
In the input to a compiler, one of the meaningful units, such as a name, constant, etc. The input is a stream of characters which the lexical analyzer breaks up into a sequence of tokens.
token ring
A local area network in which computers are configured in a ring, and a message called a token is passed from station to station. The token is used to avoid conflicts in transmission; a machine can only transmit messages while it holds the token. The most common type of token ring is defined in the IEEE 802.5 standard.
toner
The black powder which is used in an electrostatic process by laser printers and copy machines to create images on the paper.
tool palette
In a computer graphics program, the tool palette is the collection of tools available to use, such as a paintbrush, charcoal, pencil, paint bucket, airbrush, etc.
toolbar
A vertical or horizontal bar containing icons that represent the commands that can be used in an application. Sometimes the toolbar can be moved around or made to disappear.
ToolBook
A program for Windows from Asymetrix Corporation that uses a visual approach to organizing data, portraying sets of data as pages which can be grouped to make larger sets of data represented as books. ToolBook is similar to HyperCard for Macintosh, which represents data as cards and stacks of cards.
toolbox
A box or grid containing icons that represent the commands that can be used in an application. The toolbox can be moved around or made to disappear. Some programs have several toolboxes for different kinds of tools.
TOOLS
Technology of Object-Oriented Languages and Systems. A conference on objected-oriented languages and systems, organized by Interactive Software Engineering.
top-down design
A way of developing computer programs from the top down, first describing the program actions at a high level, then breaking each instruction down into its elements, which are defined in further detail, until the whole program is complete. Also called stepwise refinement.
topic drift
The tendency for newsgroup or BBS discussions to drift away from the original topic.
topology
Configuration. For example, the topology of a network shows the pattern in which the computers are interconnected. Common network topologies are the star, bus, and Token ring.
TOPS-10
The operating system for the historic DEC PDP-10 computers.
TOS
1. Terms Of Service. A stated list of the terms that must be agreed on by a user of a particular service; the terms under which a service provider provides a particular service. 2. Terms Of Service. To report a violator of America Online's Terms of Service; a user who gets TOSed too many times can lose his or her account.
TOSer
(See TOS). A malicious program whereby a hacker can kick a user off AOL permanently for no reason.
touch typing
Typing without having to look at the keyboard to find the keys. Touch typing is learned by training the fingers to find the keys and having each finger assigned to certain keys. It is much faster than the hunt-and-peck method.
touch typist
A typist who types with all ten fingers, without having to look at the keyboard to find the keys. A touch typist can work much faster than a hunt-and-peck typist.
tower
A tall case that contains the major components of a computer system. It is usually stored on the floor underneath the monitor.
TP0OSI
Transport Protocol Class 0 (Simple Class). The simplest OSI Transport Protocol. It can be used only on top of an X.25 network, or another type of network that does not lose or damage data.
TP4OSI
Transport Protocol Class 4 (Error Detection and Recovery Class). The most powerful OSI Transport Protocol. TP4OSI can be used on top of any type of network, and is the OSI equivalent to TCP.
TR
Terminal Ready. A modem status signal indicated by a light on the modem, which means a communications program is loaded and ready to run.
track
A channel where information is stored on magnetic or optical media. Tracks come in three forms: 1. The concentric rings on a floppy disk or hard disk. Tracks are recorded onto a floppy disk during formatting; a high-density floppy has 160 tracks. Disk storage is organized in tracks and sectors, which are pie-shaped slices. A combination of two or more sectors on a single track makes a cluster or block, the minimum unit used to store information. 2. On CDs and videodiscs, tracks are in spiral form. 3. On magnetic tape, tracks run parallel to the length of the tape, or diagonally for helical scan tracks.
tracks
A channel where information is stored on magnetic or optical media. Tracks come in three forms: 1. The concentric rings on a floppy disk or hard disk. Tracks are recorded onto a floppy disk during formatting; a high-density floppy has 160 tracks. Disk storage is organized in tracks and sectors, which are pie-shaped slices. A combination of two or more sectors on a single track makes a cluster or block, the minimum unit used to store information. 2. On CDs and videodiscs, tracks are in spiral form. 3. On magnetic tape, tracks run parallel to the length of the tape, or diagonally for helical scan tracks.
traffic
The amount of data traveling across a network.
transceiver
Transmitter-receiver. A device that transmits and receives data.
transient
A sudden pulse of extra voltage in a power line, lasting only a fraction of a second, which can cause damage to the computer or its files if there is no surge protector. Also called a spike.
transit network
A network used to route traffic between at least two other networks in addition to carrying its own traffic.
transmission
Sending data over a communications line.
Transmission Control Protocol
(TCP). The most common Internet transport layer protocol, defined in STD 7, RFC 793. This communications protocol is used in networks that follow U.S. Department of Defense standards. It is based on the Internet Protocol as its underlying protocol; TCP/IP means Transmission Control Protocol over Internet Protocol. TCP is connection-oriented and stream-oriented, and provides for reliable communication over packet-switched networks.
Transmission Control Protocol / Internet
(TCP/IP). The Transmission Control Protocol (TCP) on top of the Internet Protocol (IP). These protocols were developed by DARPA to enable communication between different types of computers and computer networks. The Internet Protocol is a connectionless protocol which provides packet routing. TCP is connection-oriented and provides reliable communication and multiplexing.
Transmission Control Unit
(TCU). A communications control unit which is operated exclusively by instructions programmed into the computer to which it is connected. It does not have its own internal control programs.
transmit
To send data from one point to another.
transmitter
A device that sends a signal.
transport layer
Layer 4 of the Open Systems Interconnection (OSI) networking model, which establishes and dissolves connections between hosts and makes sure transmitted data has been received. An example protocol for the transport layer is TCP.
transposition cipher
A way of enciphering a message by arranging the letters in a different order.
trap door
A means of disabling a system's security, by a hardware or software mechanism which is intentionally hidden by designers of the system, often for the purpose of providing access to service technicians or maintenance programmers.
trash can
On a Macintosh, a little picture of a trash can which is used for deleting files. The file's icon is dragged across the desktop and put in the trash. The trash can can also be used to eject floppy disks and CD-ROMs.
trashware
Badly designed or useless software.
Travan cartridge
A magnetic tape cartridge that uses .315″ tape of extended length, which makes it possible to store more data.
Travan drive
A magnetic tape drive that uses .315″ tape of extended length. Travan drives can also read and write QIC Wide tapes.
tredecillion
10^42 (U.S. and Canada); 10^78 (Europe).
trillion
10^12 (U.S. and Canada); 10^18 (Europe).
Trivial File Transfer Protocol
(TFTP). A simpler version of FTP that uses UDP (User Datagram Protocol) rather than TCP (Transmission Control Protocol) for data transport. It is easier to program than FTP but lacks directory and authentication services.
Trojan horse
A program that appears to be useful and harmless but which has harmful side effects such as destroying data or breaking security on the system on which it is run. It is similar to a virus except that it does not propagate itself as a virus does.
TRS
Tandy Radio Shack. The TRS-80 was one of the first microcomputers.
TRS-80
Tandy Radio Shack-80. One of the first personal computers on the market.
TRS-DOS
The operating system of the TRS-80, an early personal computer from Tandy Radio Shack.
Trumpet WinSock
An implementation of Winsock developed by Timothy Tattan, used widely with Windows 3. Web browsers and other programs use Winsock for communication between applications.
TSR
Terminate and Stay Resident. A kind of DOS utility that, once loaded, stays in memory after it is terminated, and can be instantly reactivated by pressing a hotkey or combination of keys. The utility will display on top of the current screen, which will return after exiting the utility. Examples of TSRs are calculators and calendars. Operating systems like Windows and MacOS have the ability to switch back and forth between applications all the time, and to have several windows open with different applications running, so TSRs are not necessary because all the programs function like TSRs.
TTY
Teletypewriter. A device that has a typewriter-style keyboard and built-in printer; it is used to send, receive, and print out signals received over telephone lines.
A Macintosh trackball made available by Kensington Microware, Ltd.
Turbo software
Software created by Borland International, Inc., including Turbo Pascal, Turbo C, Turbo Prolog, and Borland C++.
Turbogopher
A version of Gopher from the University of Minnesota.
Turtle Beach Systems
A York, Pennsylvania manufacturer of high-quality sound cards. The Multisound card is a Turtle Beach product.
TWAIN
Technology Without An Interesting Name. An open standard interface that makes it possible to capture image data from a scanner or other input device while using a graphics application (such as Photoshop). Most scanners have a TWAIN driver.
TweakUI
A shell extension that works from the computer's control panel, allowing the user to manipulate system settings such as mouse sensitivity, the speed at which menus appear, and the appearance of desktop icons.
twelve-punch
In a Hollerith card, a punch in the top row.
twiddle
To make minor changes in settings and parameters.
twinning
Writing data to more than one tape in a magnetic tape storage system, in case one copy gets damaged.
twip
Twentieth of a Point; 1/20 of a printer's point, same as 1/1440 of an inch.
twisted pair cable
The type of cable used for most telephone wiring. It has pairs of copper wires twisted together, to minimize electrical noise. There are shielded twisted pair (STP) and unshielded twisted pair (UTP) cables. In shielded twisted pair cables, each pair has a metal sheath around it for better protection against interference. Unshielded twisted pair lacks the sheath, but has the advantage of being more flexible and thinner. Twisted pair cable is being replaced over time by coaxial cables and fiber-optic cables, which have greater signal capacity.
twm
Tab Window Manager. A window manager for the X Window System.
two-wire line
A transmission line which has only two wires. An example is the line used for the regular telephone network.
TXD
Transmitting Data. A modem status signal indicated by a light on the modem, which means the local modem is transmitting data.
Type 1 font
The original, highest-quality type of PostScript outline font. Type 1 fonts are designed to print clearly at small sizes on low-resolution machines. Type 1 fonts are scalable to almost any point size because each font is a set of mathematical descriptions of letterforms as Bezier splines. A Type 1 font has two parts: the (bitmapped) screen font and the (outline) printer font. A PostScript interpreter in the printer is used to rasterize the outline font (that is, to translate the outline of each letter into an arrangement of dots, and fill in the outlines) so the type can be printed. Originally Adobe Systems, the originator of PostScript, kept the Type 1 specifications secret; others making PostScript fonts had to make Type 3 fonts, or pay a licensing fee for the Type 1 coding system. Since Adobe made the Type 1 specifications public, most PostScript types created are Type 1 fonts.
Type 2 font
A technology developed by Adobe Systems but never released.
Type 3 font
A type of PostScript font technology that was used a lot before Adobe released the Type 1 specifications publicly. Type 3 fonts can have more elaborate designs than Type 1; for example, shades of gray, graduated fills, and variable stroke widths. But they take up more memory than Type 1 fonts, take longer to print, and do not print well at small sizes.
type ahead
To type faster than the computer can accept the input; most computer programs will allow for a little typing ahead, and will catch up when the typist slows down or stops.
type ball
A metal ball that has raised characters on its surface, used to print the characters onto paper by striking an inked ribbon. Type balls with different fonts can be mounted on the head of a printer or typewriter.
type family
A group of related typefaces that are variations on the same design, such as Helvetica, Helvetica bold, Helvetica italic, Helvetica bold italic.
type font
A complete set of type characters in a particular typeface, typestyle, and size. For example, Times bold, 14 point.
type gauge
An instrument for measuring type size and leading. Often it is a clear sheet of plastic with letters of different point sizes on it, which can be laid on top of a printed page to compare the letters on the page with standard size letters on the see-through gauge. A type gauge usually includes scales of inches, picas, and points for measuring type leading and distances between other design elements on the page. It may also have examples of lines and bullets in various point sizes.
type scaler
Software that changes a scalable font into a bitmap on the spot when needed in order to display the font onscreen or print the characters. TrueType and Adobe Type Manager are examples.
type specifications
Instructions to the typesetter which indicate the desired size, style, and spacing of type on a typeset page.
type specs
Type specifications. Instructions to the typesetter which indicate the desired size, style, and spacing of type on a typeset page.
type style
The styling of the letters of a typeface. For example, the same typeface can be styled as normal, bold, italic, bold italic, underline, strikethrough, outline, shadow, and/or reverse image.
Type Twister
A program from Aldus Corporation that creates many different type effects such as shadowing, adding colors, and bending and twisting type.
typeahead
A feature of some programs that stores characters in a buffer as they are being typed, before displaying them on the screen.
typeahead buffer
A buffer storage that temporarily holds characters as they are being typed, before displaying them on the computer screen, in a program that has the typeahead feature.
typeface
The style or design of a set of characters. Examples of typefaces are Times Roman, Helvetica, and Avant Garde.
typeface family
A group of related typefaces that are variations on the same design, such as Schoolbook, Schoolbook bold, Schoolbook italic, Schoolbook bold italic.
typefounder
Someone who designs and produces typefaces; originally referred to a producer of metal type which was set by hand.
typematic
A keyboard feature that makes a kkkkkkeeeeeeyyyyyyyy repeat typing as long as it is pressed down.
typematic rate
The speed at which a character is repeated when its key is held down.
typeover mode
A typing mode in which the characters typed in replace, or type over, existing text. See insert mode.
typescript
A typewritten manuscript.
typeset
To set in type; compose.
typesetter
1. A person who keys in text to be printed and styles it according to specifications. 2. A machine used for setting type. Before the advent of desktop publishing, typesetting was done only on special typesetting machines.
typesetting
Setting material in type by hand, by means of a phototypesetter, or on a computer.
typesize
The size of type, usually given in points. Book text normally is 10, 11, or 12 point type; headings may be 14 to 18 point; chapter titles may be 20 to 36 point; footnotes may be 8 point.
typewrite
To type.
typewriter
1. A machine used to print characters on a page by striking keys on a keyboard which then strike a ribbon to make ink or carbon impressions on paper. 2. A person who types on a typewriter.
typewriting
1. Using a typewriter to set characters on a page. 2. Writing produced using a typewriter.
typewritten
Typed.
typing
1. Using a typewriter or computer keyboard to input data. 2. In programming, the classification of variables by the kind of data they contain, such as a character string, integer, etc.
typist
Someone who types on a typewriter or computer keyboard.
typo
Abbreviated expression for typographical error. A mistake in keyboarding; not hitting the intended key.
typographer
1. A printer or compositor. 2. Someone who specializes in working with type artistically, producing material that is visually appealing by choosing the appropriate styles and sizes of type and arranging the typed matter attractively on a page or other medium.
typographic
Relating to typography or typesetting.
typographical error
An error in keyboarding; not an error of content or style, simply an error caused by accidentally hitting the wrong key.
typography
1. The process of setting type by hand to produce printed material. 2. The style, placement, and overall appearance of typeset material. 3. The art of choosing and combining designs, styles, and sizes of type and arranging the typed matter to create an attractive layout.
U.S. Robotics, Inc.
(USR). A modem manufacturer in Skokie, Illinois.
U/L
Upload. To send a data transmission.
U2F
Undetectable and Untraceable Fraud. A major issue for information technology is fraud made possible by technology and electronic transactions, especially crimes that leave no trace and no audit trail.
u3b
Top-level newsgroup category for an AT&T 3B computer newsgroup.
UA
User Agent. An OSI application process that can represent a human user or an organization to the X.400 Message Handling System. The user agent creates, sends, and receives messages for the user.
UART
Universal Asynchronous Receiver Transmitter. An integrated circuit which is used for transmitting and receiving data asynchronously via the serial port on the computer. It contains a parallel-to-serial converter for data transmitted from the computer and a serial-to-parallel converter for data coming in via the serial line. The UART also has a buffer for temporarily storing data from high-speed transmissions. See universal receiver transmitter.
UBE
Unsolicited Bulk Email. Unsolicited bulk email , or spam, is an attempt by a company to get others to pay for its advertising. The costs of this kind of email are paid not by the company but by the Internet service provider and ultimately by the end user. Spam is seldom used by reputable companies. Most bulk email consists of chain letters, pyramid schemes, MMF (“make money fast”) schemes, advertisements for pornographic sites, offers of software for collecting email addresses and sending unsolicited commercial email, stock offers for unknown startup companies, etc.
UBR
(Unspecified Bit Rate). Asynchronous transfer mode (ATM) service in which available bandwidth is not guaranteed.
UCS
Universal Character Set. A character set using 16-bit character codes, also called ISO 10646. UCS is a standard defined by the International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC), and allows 65,536 (or 256 x 256) characters instead of the 256 available in ASCII. If a printer has the UCS feature, it can use a larger range of characters. The 8-bit character sets ASCII and ISO Latin 1 are subsets within UCS.
udb
Universal Debugger. An interactive source level debugger from Kendall Square Research (KSR), used for testing and debugging serial and parallel programs written in KSR, Fortran, and some other languages.
UDDI
UDDI (Universal Description, Discovery, and Integration) is an XML-based registry for businesses worldwide to list themselves on the Internet. Its ultimate goal is to streamline online transactions by enabling companies to find one another on the Web and make their systems interoperable for e-commerce. While the group does not refer to itself as a standards body, it does offer a framework for Web services integration. UDDI is often compared to a telephone book's white, yellow, and green pages. The project allows businesses to list themselves by name, product, location, or the Web services they offer.
UDF
Universal Disk Format. The volume format of DVD disks.
UDMA
Ultra DMA (Ultra Direct Memory Access). A protocol developed by Quantum Corporation and Intel for disk drives that enables the computer to take advantage of the fast Ultra ATA disk drives. UDMA/33 is twice as fast as the previous disk drive standard for PCs, supporting burst mode data transfer rates of 33.3 MBps. A further improvement is UDMA/66. See DMA.
UDP
User Datagram Protocol. A communications protocol for the Internet network layer, transport layer, and session layer, which makes it possible to send a datagram message from one computer to an application running in another computer. Like TCP (Transmission Control Protocol), UDP is used with IP (the Internet Protocol). Unlike TCP, UDP is connectionless and does not guarantee reliable communication; the application itself must process any errors and check for reliable delivery.
uemacs
MicroEmacs. A simple text editor which has versions for most personal computers and for many other computers. It is abbreviated this way because “u” looks like the Greek letter micro.
UHF
Ultra High Frequency. Electromagnetic frequencies in the range of 300 to 3000 megaherz. Used for some television and radio transmission.
UI
1. Unix International. An association that promoted an open computing environment based on UNIX System V. It disbanded in 1993 when Novell bought UNIX. 2. user interface. The combination of hardware and software that makes it possible for a user to interact with a computer or other device.
UIMX
User Interface Management System for X Windows. Interface design software from Visual Edge Software, Ltd., for Motif and Open Look.
UK Education and Research Networking Ass
(UKERNA). The organization that runs the UK educational and research network Super-JANET.
UKERNA
UK Education and Research Networking Association. The organization that runs the UK educational and research network Super-JANET.
UKUUG
United Kingdom Unix Users Group.
ULSI
Ultra Large Scale Integration. The use of integrated circuits with more than a million logic gates.
ultra high frequency
(UHF). Electromagnetic frequencies in the range of 300 to 3000 megaherz. Used for some television and radio transmission.
ultra large scale integration
(ULSI). The use of integrated circuits with more than a million logic gates.
Ultra SCSI-3
A very fast version of SCSI (Small Computer Systems Interface) which can have an 8-bit or 16-bit bus. The 8-bit version has a 50-pin adapter, transfers data at a rate of 20 megabytes per second, and can connect a maximum of 8 devices. The 16-bit version has a 68-pin adapter, transfers data at 20 to 40 megabytes per second, and can connect up to 16 devices.
Ultra-SCSI
An extension of SCSI-2 to double the transfer speed of Fast SCSI, to 20MB/second on an 8-bit connection and 40MB/second on a 16-bit connection.
Ultra64
A machine for playing Nintendo.
ultrafiche
Microfiche with images reduced 90 times or more.
ultraviolet
(UV). An invisible band of radiation having a wavelength less than 400 nanometers; beyond the visible spectrum at the violet end. Ultraviolet radiation has a wavelength shorter than visible light and longer than X-rays.
Ultrix
DEC's implementation of UNIX for the PDP-11, VAX, and DECstations.
UMA
Upper Memory Area. In a PC, the memory area between 640K and 1024K. Under DOS, this memory area is ordinarily designated for use by the ROM BIOS and display, and is unavailable for use by other programs. However, some of the free memory in this area can be used for device drivers or TSRs by implementing the commands DEVICEHIGH and LOADHIGH. See UMB.
UMB
Upper Memory Block. A block of memory in the Upper Memory Area (UMA) on a PC; TSRs and device drivers can sometimes be loaded into unused blocks of memory in this area, in order to make more space available in the conventional memory area (the first 640K on a PC).
UML
Unified Modeling Language. A notational language developed by Grady Booch, Ivar Jacobson, and Jim Rumbaugh, in cooperation with the Open Management Group (OMG), for simplifying the design of complex software, especially for object-oriented technology. UML enables the designer to visualize the overall project and make specifications as needed.
UMTS
Universal Mobile Telecommunications System.
unarchive
To bring an archived file back into active use, by decompressing it if necessary and moving it from long-term storage to an active disk.
UnArjMac
A Macintosh utility for decompressing files that have the .arj extension.
unary
Having to do with a single element or item; made up of one.
unary expression
An expression with only one operand.
unary operation
An operation with only one operand (entity that is operated on).
UNC
Uniform Naming Convention or Universal Naming Convention. A convention for specifying directories, servers, and other resources on a network, using two slashes // or backslashes to indicate the name of the server, and one slash to indicate the path or shared directory within the computer, in this format: servershare or //server/share.
uncompressor
A utility that restores a compressed file to its original size. Same as decompressor.
unconditional branch
A computer program instruction that transfers control to a different part of the program without requiring any decision.
undecillion
10^36 (U.S. and Canada); 10^66 (Europe).
undelete
To retrieve a file that was previously deleted. Some special software, such as Norton Utilities, helps in recovery of deleted files.
under construction
A sign often found on World Wide Web sites than means the site is not yet completed.
underflow
An error condition that results when a numeric value resulting from a computation is so small that the computer cannot use it to calculate with accuracy, or the number has more decimal places than will fit in the field. It can also mean an item has been called from an empty stack.
underline
ASCII character 95: _ ; also called underscore.
Undernet
An Internet Relay Chat network.
underscan
Inside of the normal viewing area on the monitor screen.
underscore
ASCII character 95: _ ; also called underline.
undetectable and untraceable fraud
(U2F). A major issue for information technology is fraud made possible by technology and electronic transactions, especially crimes that leave no trace and no audit trail.
undo
A command that undoes the last change made to a file. Some programs allow only an undo of the last change made; some allow the user to undo a series of edits, in sequence.
unencumbered virtual reality
A reality simulation that does not require a lot of equipment (such as goggles, gloves, etc.) to use it. For example, playing simulated basketball by interacting with a ball and basket on a computer screen. A video camera registers the player’s movements and shows them on the screen as if the player had actually hit the ball.
UNI
User to Network Interface. An interface between a user and a network.
unicast
Transmission from one terminal to another. Contrast with multicast, which is communication from one terminal to many.
Unicode
A character set that uses 16 bits (two bytes) for each character, and therefore is able to include more characters than ASCII, which is based on 8-bit characters. ASCII code can be used for only 256 characters, which is enough for English but not enough for languages that have more characters. Unicode can have 65,536 characters, and therefore can be used to encode almost all the languages of the world. Unicode includes the ASCII character set within it.
unicos
A version of UNIX used on Cray computers.
unidirectional
In only one direction; referring to a data channel that only transmits one way.
Uniface
An application development system from Compuware, for Macintosh, DOS, Windows, UNIX, and VMS.
unified messaging
A time-saving application tool that manages and integrates voice mail, e-mail, faxes, and pages, providing users with one convenient place to receive, view, and organize all messages.
Unified Modeling Language
(UML). A notational language developed by Grady Booch, Ivar Jacobson, and Jim Rumbaugh, in cooperation with the Open Management Group (OMG), for simplifying the design of complex software, especially for object-oriented technology. UML enables the designer to visualize the overall project and make specifications as needed.
Uniform Naming Convention
(UNC) Also called Universal Naming Convention. A convention for specifying directories, servers, and other resources on a network, using two slashes // or backslashes to indicate the name of the server, and one slash to indicate the path or shared directory within the computer, in this format: servershare or //server/share.
Unify
A relational database for UNIX, from Unify Corporation.
Unify Corporation
The company that developed Unify relational database.
uninstall
To remove installed software or hardware from the computer. Some applications must be removed with an uninstall program, which removes all files that were installed with the program and restores any modifications made to system files.
uninterruptible power supply
(UPS). A backup power supply that works when electrical power to the computer is interrupted. A small UPS can supply battery power for a few minutes so files can be saved and the computer can be shut down properly; a larger UPS can supply power for much longer.
Unipress Software, Inc.
A UNIX software company that develops applications and development tools and other products.
unique users
The number of different users who view a website within a certain time period. This is different from the number of hits, since each user could visit more than once. To identify unique users, a user registration or identification system is necessary.
Unisys Corporation
A worldwide computer company based in Blue Bell, Pennsylvania, formed from the merger of Burroughs Corporation and Sperry Corporation. Unisys supplies software and hardware from microcomputers to high-end mainframes, and is a major provider of information systems and services.
unit separator
(US). ASCII character 31: Control-_ .
UNIVAC I
Universal Automatic Computer. The world’s first electronic general purpose data processing computer, introduced in 1951, and used by the U.S. Census Bureau. UNIVAC 1 was designed and built by the Eckert-Mauchly Computer Corporation, which was later acquired by Remington Rand.
universal asynchronous receiver transmit
(UART). An integrated circuit which is used for transmitting and receiving data asynchronously via the serial port on the computer. It contains a parallel-to-serial converter for data transmitted from the computer and a serial-to-parallel converter for data coming in via the serial line. The UART also has a buffer for temporarily storing data from high-speed transmissions. See universal receiver transmitter.
Universal Character Set
(UCS). A character set using 16-bit character codes, also called ISO 10646. UCS is a standard defined by the International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC), and allows 65,536 (or 256 x 256) characters instead of the 256 available in ASCII. If a printer has the UCS feature, it can use a larger range of characters. The 8-bit character sets ASCII and ISO Latin 1 are subsets within UCS.
Universal Debugger
(udb). An interactive source level debugger from Kendall Square Research (KSR), used for testing and debugging serial and parallel programs written in KSR, Fortran, and some other languages.
Universal Disk Format
(UDF). The volume format of DVD disks.
Universal Naming Convention
(UNC) Also called Uniform Naming Convention. A convention for specifying directories, servers, and other resources on a network, using two slashes // or backslashes to indicate the name of the server, and one slash to indicate the path or shared directory within the computer, in this format: servershare or //server/share.
universal product code
(UPC). The bar code commonly found on products in retail stores, which identifies each product and makes it easy for the cashier to ring up its price. The code is read into the computer by passing it over a scanner.
universal receiver transmitter
(URT). A circuit which is used for synchronous, asynchronous, or combined synchronous/asynchronous communications, and which contains a serial-to-parallel converter for data transmitted out of the computer and a parallel-to-serial converter for data coming in. Different word lengths can be used.
universal resource locator
(URL). An Internet address which tells a browser where to find an Internet resource. For example, the URL for Computer Currents Interactive is http://www.currents.net/.
Universal Serial Bus
(USB). A personal computer bus, compatible with recently-developed Intel chips, that works at 12 Mbps and can link up to 127 peripherals in a daisy chain.
universal synchronous receiver transmitt
(USRT). A circuit which is used for synchronous data communications via the serial port on a computer. It converts data into serial form for transmission. See universal receiver transmitter and universal asynchronous receiver transmitter.
universal synchronous/asynchronous recei
(USART). A circuit which is used for synchronous or asynchronous data communications. See USRT, UART, and URT.
Universal Time Coordinated
(UTC). The same as Greenwich Mean Time (GMT). The mean solar time of the meridian of Greenwich, England, used as the basis for calculating standard time throughout the world.
UNIX
A multi-user, multitasking operating system developed by Ken Thompson, Dennis Ritchie, and others and originally licensed by AT&T's Bell Laboratories. It was originally designed for minicomputers, then revised for use on mainframes and personal computers. There are now many versions of UNIX which can be used on many different platforms. UNIX is written in the C programming language, which was also developed at AT&T. Because it allows multiple programs to run simultaneously and multiple users to access a single computer, it has been used by universities and businesses where many people use the same computer. It is the most commonly used operating system for Internet nodes.
Unix International
(UI). An association that promoted an open computing environment based on UNIX System V. It disbanded in 1993 when Novell bought UNIX.
UNIX shell account
A dialup account with an Internet Service Provider that requires the user to enter UNIX commands via a command-line interface.
UNIX Software Operation
(USO). The division of AT&T responsible for developing UNIX until it became UNIX System Laboratories (USL) in 1990.
UNIX System Laboratories
(USL). The division of AT&T which was responsible for UNIX from 1990 until it was acquired by Novell in 1993.
UNIX Systems Group
(USG). The division of Novell concerned with UNIX and UNIX products.
UNIX-to-UNIX Copy
(UUCP). A UNIX protocol that makes it possible to copy a file from one UNIX computer to another via a telephone line or direct connection. It is used for Usenet news and electronic mail. Unlike TCP/IP, UUCP requires that a session be established between the two computers in order to transfer files.
UnixWare
An implementation of UNIX System 5 released by Novell.
unload
1. To remove a disk or tape from a drive. 2. To remove a loaded program from memory. 3. To remove data from a disk or other storage device.
unmark
To deselect a selected item, group of items, or area of text.
unpack
To open a file which has been compressed with a data compression program, returning it to its original size. Data compression programs have corresponding software for unpacking compressed files when necessary; some compressed files are self-extracting.
unpacked decimal format
A form of binary decimal notation in which each decimal digit corresponds to one byte. See packed decimal format.
unshar
A UNIX utility for unpacking archives (shar files) from email and news messages.
unshielded twisted pair
(UTP). The cable used for most telephone wire, and is also used for some computer-to-computer communications. It contains pairs of unshielded wires twisted together, and is a cheap and fairly noise-free way to transmit signals. In shielded twisted pair cables, each pair has a metal sheath around it for protection against interference. Unshielded twisted pair lacks the sheath, but has the advantage of being more flexible and thinner.
unsmiley
An emoticon that is frowning or not smiling :-( rather than a smiley :-) .
unsolicited bulk e-mail
(UBE). Unsolicited bulk e-mail , or spam, is an attempt by a company to get others to pay for its advertising. The costs of this kind of e-mail are paid not by the company but by the Internet service provider and ultimately by the end-user. Spam is seldom used by reputable companies. Most bulk e-mail consists of chain letters, pyramid schemes, MMF (“make money fast”) schemes, advertisements for pornographic sites, offers of software for collecting e-mail addresses and sending unsolicited commercial e-mail, stock offers for unknown startup companies, etc.
unspecified bit rate
(UBR). Asynchronous transfer mode (ATM) service in which available bandwidth is not guaranteed.
unzip
To return a zip file (a file which has been compressed with PKZIP) to its original size (with PKUNZIP or UnZip).
up
Working; for example, a computer system is “up” if it is running.
up arrow
A keyboard key which has a picture on it of an arrow pointing upward; it moves the cursor up the page.
UPC
Universal Product Code. The bar code commonly found on products in retail stores, which identifies each product and makes it easy for the cashier to ring up its price. The code is read into the computer by passing it over a scanner.
update
The change the data in a file in order to make the data current.
upgrade
1. A newer, presumably better, version of hardware or software. 2. To make a new version of a product. 3. To install a new version of hardware or software.
uplink
1. In satellite communications, a link from an earth station to an orbiting body. 2. To transmit communications via an uplink.
upload
To transfer files or data from one computer to another. To download means
to receive; to upload means to transmit.
upper case
The capital letters on the keyboard.
upper letter row
The upper letter row (row of letter keys) on a keyboard.
Upper Memory Area
(UMA). In a PC, the memory area between 640K and 1024K. Under DOS, this memory area is ordinarily designated for use by the ROM BIOS and display, and is unavailable for use by other programs. However, some of the free memory in this area can be used for device drivers or TSRs by implementing the commands DEVICEHIGH and LOADHIGH. See Upper Memory Block.
Upper Memory Block
(UMB). A block of memory in the Upper Memory Area (UMA) on a PC; TSRs and device drivers can sometimes be loaded into unused blocks of memory in this area, in order to make more space available in the conventional memory area (the first 640K on a PC).
uppercase
Capital; referring to letters on the keyboard.
UPS
Uninterruptible Power Supply. A backup power supply that works when electrical power to the computer is interrupted. A small UPS can supply battery power for a few minutes so files can be saved and the computer can be shut down properly; a larger UPS can supply power for much longer.
upsizing
Moving from the use of small computer systems to larger ones.
upstream
1. The direction of data moving from a client to a Web server. 2. A reference to actual data that is moving from individual computers to servers. It is important to note that upstream differs from downstream due to their different transfer rates; for example, cable modems transfer data up to 30 Mbps downstream, but opnly 128 Kbps to 2 Mbps upstream.
upthread
Earlier in the discussion, in a newsgroup following a topic thread.
uptime
The time during which a computer system is operational, in contrast with downtime.
upward compatible
Describes software that is compatible with later versions of the same program. Also called forward compatible.
urban legend
A story which is not true, or only partially true, but which circulates widely and becomes a part of popular mythology. Many urban legends are propagated on the Internet, and some will go the rounds again and again.
URI
Character string that can identify any kind of resource on the Internet, including images, text, video, audio and programs. Most commom version of a URI is a URL.
URL
Uniform Resource Locator (formerly Universal Resource Locator). An Internet address which tells a browser where to find an Internet resource. For example, the URL for Computer User is http://www.computeruser.com/.
URT
Universal Receiver Transmitter. A circuit which is used for synchronous, asynchronous, or combined synchronous/asynchronous communications, and which contains a serial-to-parallel converter for data transmitted out of the computer and a parallel-to-serial converter for data coming in. Different word lengths can be used.
US
Unit Separator. ASCII character 31: Control-_ .
US legal
The standard size of paper used for legal documents in the United States, 8.5" x 14."
US letter
The standard size of business letters in the United States, 8.5" x 11."
USART
Universal Synchronous/Asynchronous Receiver Transmitter. A circuit which is used for synchronous or asynchronous data communications. See USRT, UART, and URT.
USB
Universal Serial Bus. A personal computer external bus standard which can support up to 127 peripheral devices in a daisy chain configuration, can support plug-and-play (hot plugging), and has a total bandwidth of 1.5 megabytes per second. It uses inexpensive cable, which can be up to 5 meters long.
Usenet
Users’ Network. A giant public bulletin board system on the Internet for news and electronic mail. Usenet was started in 1979 by graduate students at Duke University and the University of North Carolina, using the UUCP communications protocol. It now has over 12,000 discussion areas which cover every imaginable topic are read by millions of people all over the world. Messages and news articles are posted and users respond by email. In hot discussion areas, hundreds of messages a day may be posted. Types of Usenet groups are comp (about computers), news (about newsgroups), rec (on sports and hobbies), sci (science), soc (social), talk (discussions), misc (miscellaneous), and alt (alternative newsgroups).
Usenetter
Someone who spends a lot of time on Usenet.
USENIX
A nonprofit membership association supporting education, innovation, and research in UNIX, UNIX-like systems, open systems, and other advanced technologies. USENIX sponsors conferences, publications, tutorials, and special technical groups.
user
An individual who uses a computer, program, network, or related service for work or entertainment; usually there is a distinction between a user and a programmer or other person who works with the computer on an expert or technical level.
user agent
(UA). An OSI application process that can represent a human user or an organization to the X.400 Message Handling System. The user agent creates, sends, and receives messages for the user.
user area
A memory area that is designated for user data.
User Datagram Protocol
(UDP). A communications protocol for the Internet network layer, transport layer, and session layer, which makes it possible to send a datagram message from one computer to an application running in another computer. Like TCP (Transmission Control Protocol), UDP is used with IP (the Internet Protocol). Unlike TCP, UDP is connectionless and does not guarantee reliable communication; the application itself must process any errors and check for reliable delivery.
user group
A group of people who use a particular kind of computer. One of the best sources of advice and help a newbie can find on what software to get, how to run programs, etc., is the members of a user group. User groups often sponsor Bulletin Board Services or have Internet sites, and have meetings for anyone interested. Other benefits of user groups are software libraries, freeware downloads, information on upgrades, and special interest groups on many topics. Examples of user groups are UUGs (Unix User Groups) and MUGs (Macintosh User Groups).
user interface
(UI). The means by which a user interacts with a computer. The interface includes input devices such as a keyboard, mouse, stylus, or microphone; the computer screen and what appears on it; the way commands are given, etc. With a command-line interface, only text appears on the screen, and the user must type in commands; with a graphical user interface, windows, mice, menus, and icons are used to communicate with the computer.
User Interface Management System for X W
(UIMX). Interface design software from Visual Edge Software, Ltd., for Motif and Open Look.
user name
A name that identifies a user on a network or online service, in addition to the user's password. The user name is commonly chosen by the user.
user to network interface
(UNI). An interface between a user and a network.
user-defined
Defined by the user; the user can designate formats, dictionaries, styles, and many other parameters on the computer.
user-friendly
Easy to learn and use, especially for people who are not experts. This term is most often used to describe software.
user-obsequious
Overly user-friendly.
username
An individual name of a user on a computer network, which is used for login. It is often the first initials and last name: jmjones. The username is also the part of an email address before the @ symbol: [email protected]
USG
UNIX Systems Group. The division of Novell concerned with UNIX and UNIX products.
USL
UNIX System Laboratories. The division of AT&T which was responsible for UNIX from 1990 until it was acquired by Novell in 1993.
USO
UNIX Software Operation. The division of AT&T responsible for developing UNIX until it became UNIX System Laboratories (USL) in 1990.
usr
User. The area on a UNIX system designated for user directories and files, indicated as /usr.
USR
U.S. Robotics, Inc. A modem manufacturer in Skokie, Illinois.
USRT
Universal Synchronous Receiver Transmitter. A circuit which is used for synchronous data communications via the serial port on a computer. It converts data into serial form for transmission. See universal receiver transmitter and universal asynchronous receiver transmitter.
UTC
Universal Time Coordinated. The same as Greenwich Mean Time (GMT). The mean solar time of the meridian of Greenwich, England, used as the basis for calculating standard time throughout the world.
utility
A small helper program. Utilities are distinguished from application programs, which are used to do the main work of the computer (such as word processing, accounting, CAD), and system programs, which control the computer and run application programs. Some examples of utilities are screensavers, font managers, compression programs, and file finders.
UTP
Unshielded Twisted Pair. The cable used for most telephone wire, and is also used for some computer-to-computer communications. It contains pairs of unshielded wires twisted together, and is a cheap and fairly noise-free way to transmit signals. In shielded twisted pair cables, each pair has a metal sheath around it for protection against interference. Unshielded twisted pair lacks the sheath, but has the advantage of being more flexible and thinner.
Utra DMA
(UDMA). A protocol developed by Quantum Corporation and Intel for disk drives that enables the computer to take advantage of the fast Ultra ATA disk drives. UDMA/33 is twice as fast as the previous disk drive standard for PCs, supporting burst mode data transfer rates of 33.3 MBps. A further improvement is UDMA/66. See DMA.
UTSL
Use The Source Luke (meaning read the source code). (From Star Wars, "Use the Force, Luke.")
UU Undo
A utility that can decode uuencoded files on MacOS systems.
UUCP
UNIX-to-UNIX Copy. (Also called UNIX-to-UNIX Copy Program or UNIX-to-UNIX Copy Protocol). A UNIX protocol that makes it possible to copy a file from one UNIX computer to another via a telephone line or direct connection. It is used for Usenet news and electronic mail. Unlike TCP/IP, UUCP requires that a session be established between the two computers in order to transfer files.
UUCPNet
A network of UNIX machines around the world, on which UUCP is used for electronic mail transfer and Usenet news.
uudecode
A UNIX program that decodes uuencode files from ASCII format back to binary.
uuencode
A UNIX program that encodes binary data, 8-bit text files, and some other file formats into 7-bit ASCII files for transmission over the Internet and via e-mail. It was originally used with UUCP. The uudecode program converts the files back into their original format. Uuencoded files have .uu or .uue as a suffix.
uuencoding
A method of encoding binary data, 8-bit text files, and some other file formats into 7-bit ASCII files for transmission over the Internet. This method of encoding is common for files that are non-Macintosh or not platform-specific such as GIFs. With Mac files, uuencoding can leave out critical information, because it only encodes the data fork and strips off the resource fork; with Mac files, BinHex encoding is therefore preferred. Uuencoded files have .uu or .uue as a suffix, and can be decoded by uudecode.
UUG
Unix User Group. There are UUGs worldwide; for example, European Unix User Group (EUUG).
UUNET
(UNIX to UNIX Network). The first Internet access provider, founded in 1987 in Fairfax, Virginia, and now a full-service provider.
UUPC
UUCP (UNIX to UNIX Copy Protocol) for PCs.
UV
Ultraviolet. An invisible band of radiation having a wavelength less than 400 nanometers; beyond the visible spectrum at the violet end. Ultraviolet radiation has a wavelength shorter than visible light and longer than X-rays.
v-mail
Video mail. Sending video clips as attachments to e-mail messages.
v-net
The plain old telephone system that uses voice signals for communication.
V.21
An ITU-T modem protocol standard for asynchronous, full-duplex transmission, a data rate of 300 bits per second, and frequency shift keying (FSK) modulation.
V.22
An ITU-T modem protocol standard for synchronous and asynchronous, full-duplex transmission, with data rates of up to 1200 bits per second, and differential phase shift keying (DPSK) modulation.
V.22bis
(V.22bis means V.22 twice). An ITU-T modem protocol standard for synchronous and asynchronous, full-duplex transmission, with data rates of up to 2400 bits per second, and quadrature amplitude modulation (QAM).
V.23
An ITU-T modem protocol standard for synchronous and asynchronous half-duplex transmission at 1200 bits per second, using frequency shift keying (FSK) modulation.
V.24
An ITU-T standard that defines the way circuits are set up for an RS-232 interface between a computer and modem or other data terminal equipment and data communications equipment. It also defines modem carrier frequencies that will not interfere with regular telephone control tones.
V.25
An ITU standard for automatic modems which determines the answer tone and circuitry used.
V.25bis
An ITU standard for equipment that performs automatic calling and answering on dial-up telephone lines.
V.32
An ITU-T modem protocol standard for synchronous and asynchronous bidirectional transmission at 4800 or 9600 bits per second, using Trellis code modulation (TCM).
V.32bis
(V.32 twice). An ITU-T modem protocol standard for synchronous and asynchronous bidirectional transmission at 7200, 12000 and 14400 bits per second, using Trellis code modulation (TCM). The modem changes the speed of transmission as necessary for the transmission line used.
V.32ter
A revision of the ITU-T V.32bis modem protocol standard to allow data transmission at 19000 bits per second.
V.90
An International Telecommunication Union (ITU) standard for 56-Kbps modems.
VAC or V AC
Volts Alternating Current.
vaccine program
A computer program that watches for viruses and alerts the user if a virus is found.
vacuum tube
A sealed glass or metal container, evacuated to a high degree of vacuum, through which a controlled flow of electrons is directed. The first computers used vacuum tubes as on/off switches to indicate the 0s and 1s in digital computations. Now cathode ray tubes (CRTs) are used for computer monitors.
VAD
Value Added Dealer. Same as VAR. A company which sells something made by another company after adding something of value. For example, the VAD might put together a computer, peripherals, and specialized software, all from different companies, as a package.
valid hit
A visit to a web page that delivers all information to the user. Hits such as error messages, redirects, and computer-generated visits are not valid hits.
validation
1. The evaluation of software at the end of its development, to make sure it meets the requirements of the intended user(s). 2. The process of checking data to make sure it is correct and presented in the proper format. 3. The checking of communications packets by the receiving device.
value added dealer
(VAD). Same as VAR. A company which sells something made by another company after adding something of value. For example, the VAD might put together a computer, peripherals, and specialized software, all from different companies, as a package.
value added reseller
(VAR). A company which sells something made by another company after adding something of value. For example, the VAR might put together a computer, peripherals, and specialized software, all from different companies, as a package.
value added retailer
(VAR). A company which sells something made by another company after adding something of value. For example, the VAR might put together a computer, peripherals, and specialized software, all from different companies, as a package.
vaporware
Software that is announced long before it is ready for sale, and that sometimes never materializes.
VAR
Value Added Reseller or Value Added Retailer. A company which sells something made by another company after adding something of value. For example, the VAR might put together a computer, peripherals, and specialized software, all from different companies, as a package.
variable bit rate
(VBR). Asynchronous transfer mode (ATM) service in which bandwidth is guaranteed based on average cell rate.
variable-length field
A database field that can be expanded to the required length. For example, a field such as “Name” or “City” works better as a variable-length field, because names of people and cities vary in length. (A fixed-length field would truncate longer names and leave blank spaces on shorter names). Variable-length fields are harder to program than fixed-length fields, but can be more convenient to the user.
VAX
Virtual Address eXtension. A family of 32-bit computers from Digital which use the VMS operating system. VAXes include mainframes, minicomputers, and microcomputers. The first VAX models were released in 1977.
VAX MIPS
VAX Million Instructions Per Second. A unit of measurement of computer performance, also called VAX Unit of Performance (VUP). One VUP equals the performance of a VAX 11/780. This is also equivalent to one SPECmark.
VAX Unit of Performance
(VUP). A unit of measurement of computer performance. One VUP is equivalent to the performance of Digital Equipment Corporation’s VAX 11/780. It is also equivalent to one SPECmark.
VAXstation
A family of VAX workstations from DEC using the VMS operating system.
Vbox
A Sony hardware interface that can connect as many as 7 VCRs, videodiscs and camcorders to one serial port.
VBR
(Variable Bit Rate). Asynchronous transfer mode (ATM) service in which bandwidth is guaranteed based on average cell rate.
VBScript
Visual Basic Scripting Edition. A scripting language that is based on the Visual Basic programming language, but is much simpler and is similar to JavaScript. VBScript makes it possible to add interactive features like buttons and scrollbars to Web pages. This scripting language was developed by Microsoft and works with Internet Explorer.
VBX
Visual Basic Custom Control. A software module that can be used in many different applications. VBXs were originally created to to make it easy to develop Windows applications with Visual Basic, but can be used in other environments. The more versatile ActiveX controls advance the idea of VBX.
Vcache
The disk cache program for Windows 95.
vCard
An electronic business card format.
VCD
Video Compact Disc. A CD that can display full motion video and sound. Using 650/700MB CDs, VCD can hold up to 74/80 minutes respectively. VCDs use MPEG for compression and the quality is similar to VHS based tapes.
VCR
Video Cassette Recorder. An analog videotape player and recorder which is usually connected to a television monitor to record or play tapes. The most commonly used videotape is 1/2-inch VHS format.
VDD
Virtual Device Driver. A virtual device driver is the component of a device driver that communicates directly between an application and a hardware device. Virtual device drivers organize the flow of data to allow more than one application to access the same hardware without conflict. In the device file name, V stands for virtual and D stands for device. The “x” can be replaced with other characters; for example, VmD means a mouse driver.
Vdeck
Video Deck. A Super 8 mm tape drive from Sony which can be connected to a computer via the serial port.
VDT
Video Display Terminal. A computer terminal with monitor and keyboard; sometimes VDT refers to only the monitor.
VDU
Visual Display Unit. A computer terminal with monitor and keyboard.
vector
1. In computer graphics, a quantity represented as a line with a start and end point identified by x-y coordinates which indicate both magnitude and direction. See also vector graphics. 2. Items configured in a single column or row; a one dimensional array.
vector display
A display that uses vector graphics.
vector font
A scalable font composed of vectors (lines drawn between coordinate points).
vector graphics
A way of representing pictures by designating coordinates and drawing lines or geometric shapes in relation to them. Vector graphics are different from raster graphics, in which an image is stored as a collection of pixels. In vector graphics, the image is saved as a file containing instructions for drawing it. One advantage of vector graphics over raster graphics is that a picture can be enlarged or reduced without losing quality. Another difference is that in vector graphics, the elements of a picture (circles, squares, etc.) remain independent objects which can be edited and moved around, whereas in raster graphics, once the elements are drawn they become part of the overall pattern of pixels. A vector graphics image also requires less memory than a raster graphics image, which requires a specific memory location for each pixel.
Vector Markup Language
(VML). An application of Extensible Markup Language (XML) used for the markup of vector graphic information in the same way that HTML is used for the markup of text. VML graphics can be modified with style sheets along with the document which contains them.
vectors per second
(VPS). A measurement of the speed of a vector processor (a processor which can execute instructions in which the operands can be arrays of data rather than only single elements).
Vectra
A family of PCs developed by Hewlett Packard.
Veronica
Very Easy Rodent-Oriented Net-wide Index to Computer Archives. Veronica is a search engine for Gopher sites similar to Archie for FTP sites.
version number
The number before the decimal place in a program number (for example, Netscape Navigator 3.1, Telnet 2.6). A version number indicates a major change in a program (for example, Disinfectant 2 to Disinfectant 3), whereas a release number indicates a minor change (QuickTime 2.0 to QuickTime 2.1).
vertical application
An application created for a specific kind of business or organization, such as hospitals or retail stores. Contrast with horizontal application.
vertical bar
ASCII character 124: | . Also called vertical line.
Vertical Redundancy Check
(VRC). A way of error checking by attaching a parity bit to each byte of data to be transmitted, which is then tested to determine if the transmission is correct. See parity bit and Cyclic Redundancy Check.
vertical refresh rate
The maximum number of frames per second that a computer monitor can display, expressed in hertz. Too low a vertical refresh rate causes a flickering screen which is hard on the eyes.
vertical resolution
The number of pixels per vertical line, or the number of rows in a matrix.
vertical scaling
Adding more processors within the same multiprocessing computer system, in contrast to horizontal scaling, in which more computer systems are added.
vertical scan frequency
On a computer monitor, the number of times per second the whole screen is refreshed, expressed in hertz. Beginning at the upper left corner, the electron beam moves across the screen, then down to the next line, and to the next, until it reaches the bottom. The electron gun then moves back to the upper left corner and begins the next frame.
vertical scan rate
(VSR). The maximum number of frames per second that a computer monitor can display, expressed in hertz. Too low a scan rate causes a flickering screen which is hard on the eyes. Each frame begins with the electron gun at the upper left corner of the screen. An electron beam is scanned horizontally across the screen, making one line; it moves down slightly to make the next line, and continues until it reaches the bottom. The electron gun returns to the upper left corner to begin the next frame.
vertical software
Software created for a specific kind of business or organization, such as hospitals or retail stores. Contrast with horizontal software.
very high frequency
(VHF). Electromagnetic frequencies in the range of 30 to 300 megaherz. Used for some television and radio transmission.
very high speed integrated circuit
(VHSIC). A very high-speed computer chip which uses large-scale integration (LSI) and very large scale integration (VLSI) technology.
very large scale integration
(VLSI). The use of integrated circuits with 100,000 to a million logic gates.
very low frequency
(VLF). Electromagnetic frequencies in the range of 3 to 30 kiloherz. VLF radiation has been a source of health concerns in the use of computer monitors; standards were set by MPR II.
Very Small Aperture Terminal
(VSAT). A ground station for a communications satellite that can handle transmission rates of up to 56 kilobits per second.
very-high-level Language
(VHLL). A high-level language that is very structured, having strict rules that must be followed.
VESA
Video Electronics Standards Association. An organization which sets standards for video and multimedia in PCs. VESA established the Super VGA (SVGA) standard and the VESA Local Bus. VESA is headquartered in San Jose, California, and its members are PC vendors.
VESA Local Bus
(VLB). A local bus defined by the Video Electronics Standards Association which provides a high-speed connection between the CPU and peripherals. It allows video cards to communicate faster with the CPU. Computers with VESA Local Bus have two or three VLB slots on the motherboard, along with several ISA or EISA slots, so VESA Local Bus can be used alone or in combination with these other buses.
VFAT
Virtual File Allocation Table. The file allocation table used in Windows 95. It uses Protected Mode, an operational state that allows a PC to address all its memory.
VGA
Video Graphics Array. A video display standard for color monitors that superseded CGA and EGA. VGA monitors display 16 colors at a resolution of 640 x 480 pixels, the minimum standard display. The vertical scan frequency is around 56Hz to 60Hz. For multimedia applications, it is better to have Super VGA.
VHD
Very High Density. A 3.5″ floppy disk that holds 20 MB or more of data.
VHF
Very High Frequency. Electromagnetic frequencies in the range of 30 to 300 megaherz. Used for some television and radio transmission.
VHLL
Very-High-Level Language. A high-level language that is very structured, having strict rules that must be followed.
VHS
Video Home System. The standard home videocassette format, which has 1/2″ videotape and up to 160 minutes playing time.
VHSIC
Very High Speed Integrated Circuit. (Pronounced visik). A very high-speed computer chip which uses large-scale integration (LSI) and very large scale integration (VLSI) technology.
ViaCode
An encrypted and authenticated Internet service for businesses in the U.K., provided by The Royal Mail.
video adapter
Also called graphics adapter, display adapter, video card. A circuit board that enables a computer to display information on its screen. The resolution, number of colours, and refresh rate of a monitor is determined by the kind of video adapter used, plus the limitations of the monitor itself.
video card
Also called graphics adapter, display adapter, video adapter. A circuit board that enables a computer to display information on its screen. The resolution, number of colours, and refresh rate of a monitor is determined by the kind of video card used, plus the limitations of the monitor itself.
video cassette recorder
(VCR). An analog videotape player and recorder which is usually connected to a television monitor to record or play tapes. The most commonly used videotape is 1/2-inch VHS format.
Video CD
Video Compact Disc. A type of compact disc that can store 74 minutes of VHS-quality video along with sound of CD quality, using MPEG compression.
video display terminal
(VDT). A computer terminal with monitor and keyboard; sometimes VDT refers to only the monitor.
Video Electronics Standards Association
(VESA). An organization which sets standards for video and multimedia in PCs. VESA established the Super VGA (SVGA) standard and the VESA Local Bus. VESA is headquartered in San Jose, California, and its members are PC vendors.
video graphic card
An accelerator card to enhance 3D graphics, 2D graphics, videoconferencing, and multimedia. A videographic accelerator card can assist in delivering powerful and high-resolution throughput by performing much of the graphics processing that would otherwise be done by the CPU.
video graphic cards
Accelerator cards that enhance 3D graphics, 2D graphics, videoconferencing, and multimedia. A videographic accelerator card can assist in delivering powerful and high-resolution throughput by performing much of the graphics processing that would otherwise be done by the CPU.
Video Graphics Array
(VGA). A video display standard for color monitors that superseded CGA and EGA. VGA monitors display 16 colors at a resolution of 640 x 480 pixels, the minimum standard display. The vertical scan frequency is around 56Hz to 60Hz. For multimedia applications, it is better to have Super VGA.
Video Home System
(VHS). The standard home videocassette format, which has 1/2″ videotape and up to 160 minutes playing time.
video mail
(V-mail or vmail). Sending video clips as attachments to email messages.
video on demand
(VoD). A system by which viewers can watch video programs on their own television sets at the time they choose. The programs are supplied by cable or ISDN.
video port
The socket on the computer where the monitor cord plugs in.
video RAM
Video Random Access Memory (VRAM). A kind of high-speed memory used for the computer's display. VRAM must be fast to keep up with the speed at which the screen is scanned. The VRAM in a PC is on a display adapter card. VRAM has two ports so it can send the data for text and images to memory and to the display at the same time.
video random access memory
(VRAM). A kind of high-speed memory used for the computer's display. VRAM must be fast to keep up with the speed at which the screen is scanned. The VRAM in a PC is on a display adapter card. VRAM has two ports so it can send the data for text and images to memory and to the display at the same time.
video streaming
Playing video immediately as it is downloaded from the Internet, rather than storing it in a file on the receiving computer first. Streaming is accomplished by way of web browser plug-ins, which decompress and play the file in real time; a fast computer and fast connection are necessary.
video terminal
A cathode ray tube display screen with keyboard for input.
video window
An independent window on a computer screen in which full-motion video is displayed.
videoconferencing
Teleconferencing in which still or moving pictures can be transmitted along with voice and text. The first videoconferencing was done with analog TV and satellites, then digital video systems, using computer networks, evolved.
videodisc
An optical disc that can be used to store full-motion video.
videographer
A person who produces videos.
videographic accelerator card
An accelerator card to enhance 3D graphics, 2D graphics, videoconferencing, and multimedia. A videographic accelerator card can assist in delivering powerful and high-resolution throughput by performing much of the graphics processing that would otherwise be done by the CPU.
videography
The art of recording pictures with a video camera.
videophone
A telephone that sends and receives a video image along with voice transmission; it contains both a camera and a screen.
VideoPhone
The AT&T brand of videophones.
vigintillion
10^63 (U.S. and Canada); 10^120 (Europe).
virtual
1. (Older meaning, before computer era) Being so in essence or effect although not officially recognized (for example, a virtual paradise, meaning a place on Earth that is really like Paradise). 2. (New meaning created by computer technology) Simulated; especially simulated by electronic technology (for example, a virtual paradise, meaning a computer simulation of Paradise, perhaps in a virtual reality or 3-D gaming space).
virtual address
A memory location in a system that uses virtual memory; when an application program needs the data at that location, it is paged in and accessed by means of an address in physical memory.
virtual assistant
A hand-carried device that reads email, screens and forwards telephone calls, and handles voice mail. A virtual assistant may be activated by voice commands.
virtual company
A company that relies a lot on telecommunications and computer technology for its business activities. Some of the work may be done by telecommuting; meetings may take place by videoconferencing; the company's main point of access may be a web page.
virtual corporation
A corporation which exists primarily on the Internet. It may have a website, email address, post office box, or voice mail system which is its main point of access. Its physical resources may consist of a one or more personal computers, modems, telephones, and/or fax machines. It relies mainly on mail, telecommunications, and computer technology for its business activities. Some of the work may be done by telecommuting; meetings may take place by videoconferencing. In this way, a worldwide corporation can be run on a few home computers.
virtual device driver
(VxD). A virtual device driver is the component of a device driver that communicates directly between an application and a hardware device. Virtual device drivers organize the flow of data to allow more than one application to access the same hardware without conflict. In the device file name, V stands for virtual and D stands for device. The “x” can be replaced with other characters; for example, VmD means a mouse driver.
virtual disk
A program which simulates a hard disk drive, using part of the computer's random access memory, for fast processing of data. Files can be copied into the virtual disk and edited. The virtual disk can not store files permanently; the updates must be written to the hard disk or floppy disk before the power is turned off.
Virtual File Allocation Table
(VFAT). The file allocation table used in Windows 95. It uses Protected Mode, an operational state that allows a PC to address all its memory.
virtual hosting
The ability of a single machine to act like multiple systems, hosting more than one domain.
virtual interface
A user interface based on virtual reality; the user’s whole body interacts with the computer.
virtual LAN
Virtual Local Area Network. A division of a local area network by software rather than by physical arrangement of cables. Division of the LAN into subgroups can simplify and speed up communications within a workgroup. Switching a user from one virtual LAN to another via software is also easier than rewiring the hardware.
virtual library
A library on the Internet. There are many books and publications available online; some can be viewed on the World Wide Web and some can be downloaded via FTP.
Virtual Machine
(VM). An IBM virtual data processing system, in which multiple operating systems and programs can be run by the computer at the same time. Each user appears to have an independent computer with its own input and output devices.
virtual machine
1. (VM). A computer that does not exist as a physical device, but is simulated by another computer. 2. (VM). An IBM virtual data processing system, in which multiple operating systems and programs can be run by the computer at the same time. Each user appears to have an independent computer with its own input and output devices.
virtual machine
(VM). A computer that does not exist as a physical device, but is simulated by another computer.
virtual machine/conversational monitor s
(VM/CMS). The combination of Virtual Machine with CMS (Conversational Monitor System) to provide interactive capability. VM/CMS supports many interactive users at a time, and was designed for IBM 43xx and 30xx series computers.
virtual memory
A way of using disk storage space to make the computer work as if it had more memory. When a file or program is too big for the computer to work with in its memory, part of the data is stored on disk. This virtual storage is divided into segments called pages; each page is correlated with a location in physical memory, or RAM. When an address is referenced, the page is swapped into memory; it is sent back to disk when other pages must be called. The program runs as if all the data is in memory. The computer uses a hardware device called a memory management unit (MMU) to manage virtual memory.
Virtual Memory System
(VMS). Digital Equipment Corporation's multi-user, multitasking operating system for the VAX series of computers. As the name indicates, VMS makes use of virtual memory.
virtual office
An office that exists more in virtual space than physical space. The actual office may be little more than a computer, a telephone, a modem, and/or a fax machine. Its only communication with the outer world may be through a post office box, a voice mail system, a web page, or an email address.
virtual operating system
An operating system run by another operating system. The host computer may be able to run multiple operating systems at the same time, each giving the appearance of an independent computer with its own input and output devices.
virtual point of presence
(virtual PoP). A remote point through which a user can connect to an Internet service provider, which is not maintained by the ISP. The virtual PoP is usually established to avoid long distance telephone charges. The user calls to the virtual point of presence and the called is relayed to the ISP by a third party.
virtual printer
A way of saving printer output when the user wants to print a file but the printer is busy. The file can be “printed” to disk, where it is saved and then sent to the printer when it is no longer busy.
Virtual Private Network
(VPN). A network which has the appearance and functionality of a dedicated line, but which is really like a private network within a public one, because it is still controlled by the telephone company, and its backbone trunks are used by all customers.
virtual private networking
(VPN). A means by which certain authorized individuals (such as remote employees) have secure access to an organization's intranet by means of an extranet (a part of the internal network that is accessible via the Internet). VPN can be far less expensive than using actual private lines in a wide area network (WAN).
virtual reality
(VR). A computer simulation of reality, using 3D graphics and sound effects, often with user interfaces such as special goggles and gloves, to create a lifelike environment for entertainment, experimentation, and training.
virtual reality markup language
(VRML; also called Virtual Reality Modeling Language). A programming language which used to create the illusion of three-dimensional objects for onscreen virtual reality environments. The computer shows an apparently three-dimensional object from a certain position, and then creates the illusion of movement by gradually changing the viewpoint. The objects can be programmed to respond to mouse clicks.
virtual reality modeling language
(VRML; also called Virtual Reality Markup Language). A programming language which used to create the illusion of three-dimensional objects for onscreen virtual reality environments. The computer shows an apparently three-dimensional object from a certain position, and then creates the illusion of movement by gradually changing the viewpoint. The objects can be programmed to respond to mouse clicks.
virtual screen
A viewing area that extends beyond the physical boundaries of the computer display screen. The extended area can be seen by scrolling, allowing the user to look at very large documents or multiple documents placed side by side.
Virtual Sequential Access Method
(VSAM). A data storage system used in IBM mainframes. VSAM was designed to improve access time by searching indexes instead of actual files, and organizing data efficiently.
Virtual Software Factory
(VSF). A tool for Computer Aided Software Engineering (CASE) from Systematica.
virtual storage
A way of using disk storage space to make the computer work as if it had more memory, also called virtual memory. See virtual memory.
Virtual Storage Access Method
(VSAM). An IBM program that controls communication and data flow in SNA networks.
Virtual Telecommunications Access Method
(VTAM). Software for controlling communications between terminals and application programs in IBM and IBM-compatible systems. It is compatible with Systems Network Architecture.
Virtual Terminal
(VT). The OSI Virtual Terminal Service. Similar to Telnet, it allows users of one host to log into a remote host and interact as if they are normal terminal users of that host.
virus
A program that infects a computer by atttaching itself to another program, and propagating itself when that program is executed. A computer can become infected by files downloaded over a network, or by the installation of new software or floppy disks that are infected with viruses. Some viruses are only pranks, and perform harmless actions like displaying a screen with a joke message on it. Others can destroy files or wipe out a hard drive. To avoid damage from viruses, write-protect the boot disk and other important disks, check new software or disks for viruses, and have virus protection software installed on the computer at all times. Disinfectant programs must be updated periodically because new viruses get into circulation over time. There are some virus protection programs available on the Internet for free. Disinfectant for Macintosh, written by John Norstad of Northwestern University, is freeware; McAfee Anti-Virus for the PC is a shareware program. Knowingly spreading a computer virus is a crime punishable by law. See also Trojan horse and worm.
virus signature
The binary pattern of a virus, used by the antivirus program to detect and eliminate the virus.
VisiCalc
The first spreadsheet program for computers, created by Dan Bricklin and Bob Frankston in 1978 for the Apple II.
Visual Basic
A visual programming environment from Microsoft, used for developing Windowsapplications. Visual Basic makes it possible to develop practical programs very quickly. The programmer designs windows graphically, then drags program elements, represented by icons, from the Visual Basic Toolbox, and writes Basic code for each element. Visual Basic is event-driven; procedures are called automatically when the end-user chooses menu items, clicks the mouse, moves objects on the screen, etc.
Visual Basic Custom Control
(VBX). A software module that can be used in many different applications. VBXs were originally created to to make it easy to develop Windows applications with Visual Basic, but can be used in other environments. The more versatile ActiveX controls advance the idea of VBX.
Visual C++
A development environment for C and C++ from Microsoft .
Visual dBASE
A version of dBASE designed to enable developers to present data on the World Wide Web.
visual display unit
(VDU). A computer terminal with monitor and keyboard.
Visual User Environment
(VUE). A graphical user interface for UNIX from Hewlett-Packard.
Visual User Interface Tool
(VUIT). A Digital Equipment Corporation tool for creating applications interfaces with OSF/Motif.
VLB
VESA Local Bus. A local bus defined by the Video Electronics Standards Association which provides a high-speed connection between the CPU and peripherals. It allows video cards to communicate faster with the CPU. Computers with VESA Local Bus have two or three VLB slots on the motherboard, along with several ISA or EISA slots, so VESA Local Bus can be used alone or in combination with these other buses.
VLF
Very Low Frequency. Electromagnetic frequencies in the range of 3 to 30 kiloherz. VLF radiation has been a source of health concerns in the use of computer monitors. The Swedish guidelines called MPR II define acceptable levels; some monitors are designed to meet these guidelines.
VLSI
Very Large Scale Integration. The use of integrated circuits with 100,000 to a million logic gates.
VM
1. Virtual Memory. A way of using disk storage space to make the computer work as if it had more memory. When a file or program is too big for the computer to work with in its memory, part of the data is stored on disk. This virtual storage is divided into segments called pages; each page is correlated with a location in physical memory, or RAM. When an address is referenced, the page is swapped into memory; it is sent back to disk when other pages must be called. The program runs as if all the data is in memory. The computer uses a hardware device called a memory management unit (MMU) to manage virtual memory. 2. Virtual machine. A computer that does not exist as a physical device, but is simulated by another computer. 3. Virtual Machine. An IBM virtual data processing system, in which multiple operating systems and programs can be run by the computer at the same time. Each user appears to have an independent computer with its own input and output devices.
VM/CMS
Virtual Machine/Conversational Monitor System. The combination of Virtual Machine with CMS (Conversational Monitor System) to provide interactive capability. VM/CMS supports many interactive users at a time, and was designed for IBM 43xx and 30xx series computers.
VmD
Virtual device driver for a mouse.
VML
Vector Markup Language. An application of Extensible Markup Language (XML) used for the markup of vector graphic information in the same way that HTML is used for the markup of text. VML graphics can be modified with style sheets along with the document which contains them.
Top-level newsgroup category for a VAX/VMS system newsgroup.
VoD
Video on Demand. A system by which viewers can watch video programs on their own television sets at the time they choose. The programs are supplied by cable or ISDN.
voice activated
Activated by spoken commands rather than by typing commands into a keyboard, clicking with a mouse, or pushing buttons.
voice channel
A communications channel used to transmit human voice.
voice grade
The bandwidth necessary for transmitting the human voice, usually about 4,000 Hz.
voice mail
A computerized system for receiving, recording, and sometimes forwarding audio messages. A voice mail system plays a prerecorded message to the caller when the line is not answered, and may provide choices such as paging, talking to an operator, or selecting a number by touchtone to choose between message boxes.
voice messaging
The recording of voice messages, even when the receiver of the message is available to listen; used as an alternative to email.
voice recognition
The ability of a computer to recognize spoken words. A computer with voice recognition software can respond to simple spoken commands. In some voice recognition systems, the computer can be programmed to respond only to a particular speaker, by comparing spoken commands with a sound sample.
voice-activated dialing
A feature that allows a user to dial a telephone by speaking; the phone responds to the user’s spoken commands to dial telephone numbers that are pre-programmed in its memory.
voice-net
The plain old telephone system.
voice-over IP
Also called Internet telephony, Voice-over IP (VoIP) uses the Internet Protocol (IP) to transmit voice communications over intranets, extranets, and the Internet. VoIP provides an alternative to standard telephone communication, especially for Internet users with free or fixed-price Internet access, as they can essentially call anywhere around the world for free using Internet telephony software). VoIP sends digitized audio in packet form.
volatile memory
Memory that loses its content when the power is shut off. The main memory (Random Access Memory or RAM) of the computer is volatile memory. Any changes made to files must be saved to disk before the power is turned off or they will be lost. ROM (Read-Only Memory) is non-volatile memory.
volatile storage
Storage or memory which is not permanent; with volatile storage the data is lost when the electrical power is off. A computer’s main memory (RAM) is ordinarily volatile, although there is non-volatile RAM.
volatile storage
Storage that loses its content when the power is shut off, such as Random Access Memory (RAM). Disks and tapes are non-volatile storage media.
volt
The International System unit of electric potential and electromotive force. (Named after Count Allesandro Volta, Italian physicist, 1745-1827). If one volt is applied to a resistance of one ohm, a current of one ampere will flow across the resistance.
volt-amperes
Volts times amperes; an electrical measurement. For direct current, one volt-ampere equals the same power as one watt.
volt-amps
Volts times amperes; an electrical measurement. For direct current, one volt-amp equals the same power as one watt.
voltage regulator
A device which maintains constant voltage in an electrical line in case of brownout.
volume
1. Sound level. 2. A data carrier, such as a disk, a reel of magnetic tape, or a unit of logical storage.
Volume Table of Contents
(VTOC). A table of contents on a disk or diskette that describes the location and size of each file. VTOC is generally a term used with mainframes; personal computers use the term File Allocation Table.
von Neumann architecture
The architecture of computers in which one instruction is processed at a time, also called serial architecture. John von Neumann (1903-1957), Hungarian mathematician, outlined this idea in 1945. Since then, other concepts have evolved, and parallel processing, in which many instructions are processed similtaneously, is often used for faster results.
von Neumann, John
A Hungarian mathematician (1903-1957) who outlined the basic structure of digital computers when working at Princeton in 1945. Von Neumann envisioned the computer with 5 basic units: 1. an arithmetic unit to perform calculations.; 2. a central processing unit; 3. a memory unit to store data and instructions; 4. an input unit to receive data and instructions; 5. an output unit. The von Neumann concept included serial architecture, which means the computer processes one instruction at a time, although very quickly. The first all-electronic computer, ENIAC, realized von Neumann's vision in 1946.
Voodoo
The chip used by 3DFX, for more powerful 3D graphics.
Voters Telecommunications Watch
(VTW). An organization concerned with the rights of Internet citizens; VTW has supported free speech on the Internet and opposed restrictions on encryption technology. VTW is known for the “Free Speech” fireworks icon displayed on web pages.
voxel
(Volume pixel, or volume picture element). A three-dimensional pixel; a concept used in three-dimensional modeling. The smallest division of a three-dimensional space or image.
Voyager
A virtual reality modeling language (VRML) viewer for Macintosh.
VPN
Virtual Private Networking . A means by which certain authorized individuals (such as remote employees) have secure access to an organization's intranet by means of an extranet (a part of the internal network that is accessible via the Internet). VPN can be far less expensive than using actual private lines in a wide area network (WAN).
VPS
Vectors Per Second. A measurement of the speed of a vector processor (a processor which can execute instructions in which the operands can be arrays of data rather than only single elements).
VR
(Virtual Reality). A computer simulation of reality, using 3D graphics and sound effects, often with user interfaces such as special goggles and gloves, to create a lifelike environment for entertainment, experimentation, and training.
VRAM
Video Random Access Memory. A kind of high-speed memory used for the computer's display. VRAM must be fast to keep up with the speed at which the screen is scanned. The VRAM in a PC is on a display adapter card. VRAM has two ports so it can send the data for text and images to memory and to the display at the same time.
VRC
Vertical Redundancy Check. A way of error checking by attaching a parity bit to each byte of data to be transmitted, which is then tested to determine if the transmission is correct. See parity bit and Cyclic Redundancy Check.
VRML
Virtual Reality Modeling Language or Virtual Reality Markup Language. A programming language which used to create the illusion of three-dimensional objects for onscreen virtual reality environments. The computer shows an apparently three-dimensional object from a certain position, and then creates the illusion of movement by gradually changing the viewpoint. The objects can be programmed to respond to mouse clicks.
VRML Consortium, Inc.
The VRML Consortium, Inc. is a nonprofit corporation dedicated to promoting VRML (Virtual Reality Modeling Language) as the open standard for 3D multimedia and shared virtual worlds on the Internet.
VSAM
1. Virtual Storage Access Method. An IBM program that controls communication and data flow in SNA networks. 2. Virtual Sequential Access Method. A data storage system used in IBM mainframes. VSAM was designed to improve access time by searching indexes instead of actual files, and organizing data efficiently.
VSAT
Very Small Aperture Terminal. A ground station for a communications satellite that can handle transmission rates of up to 56 kilobits per second.
VSF
Virtual Software Factory. A tool for Computer Aided Software Engineering (CASE) from Systematica.
VSR
Vertical Scan Rate. The maximum number of frames per second that a computer monitor can display, expressed in hertz. Too low a scan rate causes a flickering screen which is hard on the eyes. Each frame begins with the electron gun at the upper left corner of the screen. An electron beam is scanned horizontally across the screen, making one line; it moves down slightly to make the next line, and continues until it reaches the bottom. The electron gun returns to the upper left corner to begin the next frame.
VT
1. Vertical Tab; ASCII character 11. 2. Virtual Terminal. The OSI Virtual Terminal Service. Similar to Telnet, it allows users of one host to log into a remote host and interact as if they are normal terminal users of that host.
VT100
A video terminal from DEC, released in the 1980s, that became a standard. VT200 and VT300 models followed.
VTAM
Virtual Telecommunications Access Method. Software for controlling communications between terminals and application programs in IBM and IBM-compatible systems. It is compatible with Systems Network Architecture.
VTOC
Volume Table of Contents. A table of contents on a disk or diskette that describes the location and size of each file. VTOC is generally a term used with mainframes; personal computers use the term File Allocation Table.
VTW
Voters Telecommunications Watch. An organization concerned with the rights of Internet citizens; VTW has supported free speech on the Internet and opposed restrictions on encryption technology. VTW is known for the “Free Speech” fireworks icon displayed on web pages.
vtwm
An extended version of Tab Window Manager, which provides a virtual desktop.
VU/Text Information Services, Inc.
An online service based in Philadelphia, Pennsylvania, that provides access to newspapers.
VUE
Visual User Environment. A graphical user interface for UNIX from Hewlett-Packard.
VUIT
Visual User Interface Tool. A Digital Equipment Corporation tool for creating applications interfaces with OSF/Motif.
VUP
VAX Unit of Performance. A unit of measurement of computer performance. One VUP is equivalent to the performance of Digital Equipment Corporation’s VAX 11/780. It is also equivalent to one SPECmark.
VxD
Virtual Device Driver. A virtual device driver is the component of a device driver that communicates directly between an application and a hardware device. Virtual device drivers organize the flow of data to allow more than one application to access the same hardware without conflict. In the device file name, V stands for virtual and D stands for device. The “x” can be replaced with other characters; for example, VmD means a mouse driver.
W
Wait.
W-O
Write Once. Refers to storage media such as WORM and CD-R on which data can be written once, but not erased or rewritten.
W3
WWW; the World Wide Web. A hypermedia-based system for browsing Internet sites. It is named the Web because it is made of many sites linked together; users can travel from one site to another by clicking on hyperlinks. Text, graphics, sound, and video can all be accessed with browsers like Mosaic, Netscape, or Internet Explorer. The Web can also be accessed with text-only browsers like Lynx. 2. A World Wide Web browser for Emacs.
W3 Consortium
World Wide Web Consortium (W3C); also called W3O. The main body that creates standards for the World Wide Web. Based at the Massachusetts Institute of Technology (MIT), it also produces reference software.
W3C
W3 Consortium (World Wide Web Consortium); also called W3O. The main body that creates standards for the World Wide Web. Based at the Massachusetts Institute of Technology (MIT), it also produces reference software.
W3O
World Wide Web Consortium; also called W3C. The main body that creates standards for the World Wide Web. Based at the Massachusetts Institute of Technology (MIT), it also produces reference software.
WAA
Wide Area Adapter. An adapter connecting to a wide area network (WAN).
wabbit
A computer program that is not a virus or worm but that makes copies of itself every time it is run, which eventually crashes the system. The original “wabbit” appeared in the late 1970s.
WABI
Windows ABI (Windows Application Binary Interface). A software package from SunSoft that provides Microsoft Windows emulation for UNIX. It translates calls made by Windows applications into X Window calls.
WACK
Wait before sending positive acknowledgement. This means the receiving station is not ready to receive the ACK.
wafer
A very thin sheet of semiconductor material, about 1/30″ thick, which comprises the substrate for a microchip.
WAIS
Wide Area Information Server. A search engine developed by Thinking Machines, Inc., which can find documents on the Internet. WAIS uses keywords to search text files, and can search the entire contents of documents rather than only titles. WAIS uses the ANSI Z39.50 query language.
wait state
A brief delay added before a microprocessor executes an instruction, to allow time for slower memory chips or external devices to respond. A wait states may be one or more of the computer's clock cycles or may be timed differently. One wait state on each access of memory can make the processor up to 20% slower. With no wait state (called zero wait state) the processor will run faster.
waiting time
The time lag between the beginning of a request for data and the moment it begins to be received; also called latency.
waldo
A mechanical arm or other extension of a human limb, which is operated by a human and used to do various tasks. The term originates in Robert Heinlein's science fiction story, “Waldo”.
wall
A UNIX command meaning “write all”. It sends a message to everyone logged in at the time.
wall time
The time according to a clock on the wall, rather than on the computer's clock.
wall wart
A transformer plugged into a wall outlet that converts the AC power from the outlet into DC power for an electronic device such as a modem. Also called a power adapter.
wallpaper
A picture or pattern displayed as a background to the windows or other items on the computer's desktop in a graphical user environment. The user can choose the wallpaper from a group of available patterns, or create original wallpaper.
WAN
Wide Area Network. A network in which computers are connected to each other over a long distance, using telephone lines and satellite communications. Contrast with Local Area Network (LAN).
Wang Laboratories
Wang Laboratories, Inc. A Lowell, Massachusetts computer systems and software company founded by Dr. An Wang. Some Wang Labs products have been desktop calculators, WPS word processors, and VS minicomputers.
Wang, Dr. An
The founder (in 1951) of Wang Laboratories, Inc. Originally from China, Dr. Wang studied at Harvard University in the U.S. One of his inventions was a pulse transfer device that made it possible to use magnetic cores for computer memory. He was inducted into the National Inventors Hall of Fame in 1988.
WAP
(Wireless Application Protocol). A global standard for developing applications over wireless communication networks.
WAP gateway
When implementing services in Wireless Application Protocol (WAP), information is translated into Wireless Markup Language (WML) by a two-way device called a WAP gateway.
warez
Software that is illegally made available, for example on an FTP or Telnet site, by software pirates.
warm boot
Restarting the computer without turning the power off. Same as soft boot; the opposite of cold boot.
warm start
Restarting the computer without turning the power off. The opposite of cold start.
warm swap
To replace a component without turning the power off. Although the computer system is on, the component itself must not be in use.
Warp
IBM's OS/2 version 3.0.
warp speed
Faster than the speed of light; a science fiction concept explaining how spaceships can travel over vast interstellar distances.
Warp Zillion Opus to Opus
(WaZOO). The session layer protocol for Fidonet. WaZOO is sometimes used for other Internet transmissions.
watch icon
A little wristwatch symbol that replaces the normal mouse pointer symbol to indicate the computer is working on something and temporarily unavailable to receive new commands. The watch icon usually appears in Macintosh programs; in Windows programs there is an hourglass.
Watcom compiler
One of a series of C and FORTRAN compilers for 16- and 32-bit Intel-processor PCs from Watcom International Corporation.
Watcom International Corporation
A company in Waterloo, Ontario, Canada that is a subsidiary of Powersoft Corporation. Watcom provides application development tools, C and FORTRAN compilers, SQL database servers, and other products. Some well-known Watcom products are WATFOR, Watcom SQL, Watcom C/C++, and Watcom VX*REXX.
Watcom SQL
A relational database management system (RDBMS) from Watcom International, which can be used on systems from large local area networks to single PCs. It is available for DOS, NetWare, OS/2, and Windows.
Watcom VX*REXX
An integrated visual development environment from Watcom International Corporation.
water MIPS
Water-cooled mainframes or supercomputers. See MIPS.
watermark
A watermark is a normally invisible pressure mark in expensive paper which can be seen only when the paper is held up to the light. Some computer files have digital watermarks embedded in them as a pattern of bits which appear to be part of the file and are not noticeable to the user. These patterns can be used to detect unauthorized copies.
WATS
Wide Area Telephone Service. A WATS line is a service in which a subscriber pays a flat monthly rate for unlimited long-distance calls to certain calling areas.
watt
(After James Watt, Scottish inventor). A unit of electrical power produced by a current of one ampere across a potential difference of one volt, or a unit of power equal to one joule per second.
Watt, James
A Scottish engineer and inventor (1736-1819), who invented the steam engine. See watt.
WAV
A digitized audio file format for Microsoft Windows that stores sounds as waveforms. It has “.wav” as the filename extension.
WAVE
A language for robotics.
wave
An oscillation or movement that transfers energy from point to point; that can be described mathematically in terms of its frequency, amplitude, velocity, and phase; and that can be visualized as a moving swell or succession of curves. Light, sound, electricity, and many other signals travel in waves.
wave file
A file which contains a representation of sound waves in digital form.
waveform
1. The pattern of a sound wave or other wave; the change of a sound wave's amplitude over time. 2. A graphic representation of the pattern of a wave showing characteristics such as frequency and amplitude.
wavelength
In a periodic waveform, the distance between one point on a wave and the same point in the next cycle. The waveform can be determined mathematically by dividing the speed by the frequency.
Wavelength Division Multiplexing
(WDM). A technology for transmitting multiple signals at the same time over a single optical fiber. The signals travel within color bands, with one color band for each signal.
wavelet
A little wave, limited in duration and frequency.
wavelet transform
A method of converting a signal into a series of wavelets, for efficient storage. One of its computing applications is in lossy compression for color graphics.
wavetable synthesis
Synthesizing musical instrument sounds by using stored digital information taken from sound produced by real instruments. The sampling rate determines the quality of sound. Compare FM synthesis.
WaZOO
Warp Zillion Opus to Opus. The session layer protocol for Fidonet. WaZOO is sometimes used for other Internet transmissions.
WCDMA
Wideband CDMA. A high-speed G3 mobile wireless technology officially known as “IMT-2000 direct spread.” The technology works by digitizing and transmitting the input signals in a coded, spread spectrum mode over a range of frequencies. WCDMA has the ability to spread its transmissions over a 5MHz carrier and it supports images, mobile/portable voice, data and video communications at up to 2 Mbps for local area access or 384 Kbps for wide area access.
WD
Western Digital. A company in Irvine, California, that manufactures hard disk drives, integrated circuits, graphics adapters, and other products.
WDM
Wavelength Division Multiplexing. A technology for transmitting multiple signals at the same time over a single optical fiber. The signals travel within color bands, with one color band for each signal.
WE
A system of hypertext authoring from the University of North Carolina.
Weather Observation Definition Format
Also called Weather Observation Markup Format (OMF); an application of XML used for weather observation reports, forecasts, and advisories.
Weather Observation Markup Format
(OMF). The Weather Observation Markup Format is an application of XML used to encode weather observation reports, forecasts, and advisories.
Web
The World Wide Web (WWW). A hypermedia-based system for browsing Internet sites. It is named the Web because it is made of many sites linked together; users can travel from one site to another by clicking on hyperlinks. Text, graphics, sound, and video can all be accessed with browsers like Mosaic, Netscape, or Internet Explorer. The Web can also be accessed with text-only browsers like Lynx.
Web browser
A program such as Mosaic, Netscape, Internet Explorer, and others that are used to view pages on the World Wide Web.
Web cam
Web camera. A digital camera that uploads images to a Web site for broadcast.
Web crawler
A program which visits remote sites and automatically downloads their contents for indexing. Web crawlers are part of the effort to organize the millions of documents on the World Wide Web. See also WebCrawler.
Web Design
The art of constructing an appealing and functional design which will serve the dual purpose of producing an aesthestically pleasing look as well as an easy-to-use navigational scheme.
Web designer
A person who designs pages for the World Wide Web. Web page design requires computer graphic design skills plus knowledge of HTML and how to convert graphic images and sound files into web formats.
Web Hosting
A web hosting company (usually an ISP) leases server space and web services to companies and individuals who wish to present a web or e-commerce presence but do not wish to maintain their own servers. The servers are connected to the same fast internet backbone as the ISP. Cost structures are determined by the amount and complexity of services offered such as Scripting Tools, SQL Databases, Credit Card Processing, etc.
Web page
One page of a document on the World Wide Web. A web page is usually a file written in Hypertext Markup Language (HTML), stored on a server. A web page usually has links to other web pages. Each web page has its own address called a Uniform Resource Locator (URL), in the form http://www.computeruser.com.
Web page designer
A person who designs a web page. Web page design requires computer graphic design skills plus knowledge of HTML and how to convert graphic images and sound files into web formats.
Web PC
A specially-designed computer that is only for surfing the Internet.
Web publishing
Creating hypertext documents and making them available on the World Wide Web. Web documents can include many different media, and often have text, pictures, animated graphics, sound and movie clips, and interactive forms. Web pages can also contain hyperlinks to other documents, electronic mail links, and search engines. To publish a document on the World Wide Web, one must store it on a computer that is a web server, and make its address known by linking it to other web pages and perhaps registering it with directory services.
Web server
A server on the Internet that holds World Wide Web documents and makes them available for viewing by remote browsers.
Web site
A server computer that makes documents available on the World Wide Web. Each Web site is identified by a hostname.
Web smith
A person who develops and maintains a website; also one who creates web pages.
Web Standards Project
(WSP). An initiative by WWW developers and users to stop fragmentation of the Web, by establishing standards for browsers and encouraging browser makers to follow them.
WebBench
A benchmark for measuring the performance of Web server software by running different Web server packages on the same server hardware or by running a given Web server package on different hardware platforms. WebBench has both static test suites, which test only HTML pages, and dynamic tests suites, which use a combination of common gateway interface (CGI) scripts and static requests.
webcast
Broadcasting information over the World Wide Web.
WebCrawler
A World Wide Web index and search engine, http://webcrawler.com/. See also Web crawler.
WebFX
A virtual reality modeling language (VRML) viewer for Windows.
webhead
A person who is enthusiastic about the World Wide Web and uses it a lot.
webmaster
The person who administers a website. The webmaster is often also the designer of some or all of the site’s pages.
WebSpace
The first virtual reality modeling language (VRML) viewer, from SGI.
WebTV
WebTV is a way of accessing Internet and email service via a set-top box, a television set, a standard phone line, and a subscription-based online service called WebTV Network.
WebWasher
An Internet filtering program from Siemens, downloadable free of charge to private users. Using WebWasher, users can filter unsuitable or unwanted material, including pornography, advertisements, banner images, and large tables. Using the program, the volume of data transmitted can be reduced by up to 45 percent. In this way, users can choose which contents they wish to view and do not have to pay transmission fees for unwanted material.
webzine
A magazine on the World Wide Web.
well-behaved
Acting in accordance with standards; software is said to be well-behaved if it uses the operating system in the expected way for such tasks as screen display, keyboard input, disk input/output, etc. Programs called ill-behaved are designed to bypass normal operating system functions, which may result in better performance but makes the program less portable and more likely to be restricted to specific hardware.
Western Digital Corporation
A company in Irvine, California, that manufactures hard disk drives, integrated circuits, graphics adapters, and other products.
Westlaw
An online service from West Publishing Co., Eagan, Minnesota, that offers access to legal databases, plus Knight-Ridder and Dow Jones.
Westmount Technology
A Netherlands software company that produced Real Time Engineering Environment (RTEE).
wetware
Human beings, or the human nervous system, as opposed to computer hardware or software.
WFW
Windows for Workgroups (3.1). A version of Windows 3.1 which is specifically designed to be used with a network.
WG
Working Group. A group of people working on a particular project. This term is often used for groups of people who are developing new technology in computing.
whack
To modify a program without knowing how it works. A whacker is a would-be hacker.
whacker
An incompetent hacker.
what if?
A way of using a spreadsheet to make predictions by changing certain items of data and seeing how other items are affected. For example, “What if all the prices are raised 10%?”
What You See Is What You Get
(WYSIWYG). Refers to the ability of a computer to present an image of a page layout or graphic on its screen that shows how the actual page will look like when it comes out of the printer. Before advanced computer technology made WYSIWYG possible, a typesetter formatting a page would see only unformatted lines of type and coding on the screen, and would have to hope that the copy that came out would look the way it was supposed to.
What You See Is What You Print
(WYSIWYP). Refers to the ability of a computer to display the same colors and resolution on the screen that will come out of the printer. Calibrating the printer and monitor and using a color matching system make it possible to match screen display and finished product.
What's New
The space on a website where the latest changes and updates are announced.
wheel
A privileged user on a computer system; a user who has a wheel bit.
wheel bit
A bit that gives a user special privileges on a system.
wheel mode
A privileged logon; a mode in which a user has special privileges not available to all users.
Whetstone
A benchmark for floating point operations, named after Whetstone, a town in England. The results of the test are given in Whetstones per second.
Which Stands For Nothing
(WSFN). A beginning programming language for Atari computers.
WHIRLWIND
An early mainframe developed at Massachusetts Institute of Technology in the 1940s and 1950s. It was the first example of a digital electronic computer with magnetic core memory, and took up two floors of a building at MIT.
white noise
Interference generated by the movement of electricity in a communications line. Also called Gaussian noise.
white pages
A directory service which is comparable to the white pages of the telephone directory. The Internet has a number of databases for finding people by name, email address, snail mail address, and telephone number; examples are Knowbot Information Service, Netfind, Finger, and whois.
white point
The point defined as white on a color display. It is defined as 6500 degrees Kelvin, or as x=0.3127, y=0.3290 on the CIE Chromaticity Diagram.
white space
Blank spaces on a printed page, inserted in the text by characters such as spaces, tabs, line feeds, and form feeds.
whiteboard
The equivalent of a blackboard, but on a computer screen. A whiteboard allows one or more users to draw on the screen while others on the network watch, and can be used for instruction the same way a blackboard is used in a classroom.
whois
An Internet directory service which can be used to find information about users registered on a server, or other information about the network.
Whurlwind
A virtual reality modeling language (VRML) viewer for Macintosh.
wide area adapter
(WAA). An adapter connecting to a wide area network (WAN).
Wide Area Information Server
(WAIS). A search engine developed by Thinking Machines, Inc., which can find documents on the Internet. WAIS uses keywords to search text files, and can search the entire contents of documents rather than only titles. WAIS uses the ANSI Z39.50 query language.
wide area network
(WAN). A network in which computers are connected to each other over a long distance, using telephone lines and satellite communications. Contrast with local area network (LAN).
DOS and UNIX, ? can be used to represent any single character, and * can represent any group of characters. Therefore, “*.*” could be substituted for any file name; “*.BAK” would mean any .BAK (backup) file, etc.
WIMP
Windows, Icons, Menus, and Pointers; or Windows, Icons, Mouse, Pull-down Menus. A WIMP interface is a graphical user interface such as used in Macintosh, Microsoft Windows, OSF/Motif, NeWS, RISC OS, and the X Window System. The first graphical user interface was developed at Xerox Palo Alto Research Center.
WIMP user interface
Windows, Icons, Menus, and Pointers; or Windows, Icons, Mouse, Pull-down Menus. A WIMP user interface is a graphical user interface such as used in Macintosh, Microsoft Windows, OSF/Motif, NeWS, RISC OS, and the X Window System. The first graphical user interface was developed at Xerox Palo Alto Research Center.
Win 95
Windows 95. An operating system with graphical user interface from Microsoft, which can run 32-bit applications. Windows 95 was a major upgrade from earlier versions of Windows up to Windows 3.1, which simply provided a graphical user interface for DOS. Some features of Windows 95 are Plug and Play capability, threading, pre-emptive multitasking, and built-in networking. The user interface has icons and folders similar to Macintosh, and allows the use of long file names. The minimum requirements for a computer to run Windows 95 are an 80386 or Pentium CPU and at least 8 megabytes of RAM.
Win NT
Windows NT (Windows New Technology). A 32-bit operating system from Microsoft for high-end workstations, servers, and networks. It has built-in networking, pre-emptive multitasking, multi-threading, memory protection, and fault tolerance. It can be used on PCs and other types of computers, including DEC Alpha. Windows NT supports the Unicode character set, which allows more characters than standard ASCII. The minimum requirements for Windows NT are an 80386 processor, and at least 12 megabytes of RAM. Windows NT has become especially popular as a server because of its extra security features.
Win32s
An extension for Windows 3 which allows it to run 32-bit applications.
WinBench
A series of tests from Ziff-Davis' PC Labs that analyze computer performance in a Windows environment. Results are given in Winmarks.
WinBench 97
A benchmark from Ziff-Davis that measures the performance of a PC’s graphics, disk, processor, video and CD-ROM subsystems in a Windows environment. WinBench 97's tests are all 32-bit, except for the 16-bit processor test, and can only run on Windows 95 and Windows NT systems.
Winchester drive
A hard disk drive that has a movable read/write head which planes over the surface of the disk on a cushion of air produced by the rotation of the disk. When the disk stops rotating, the read/write head comes to rest in a landing zone on the disk where no data is stored. Winchester drives are kept in a sealed unit which protects the disks from dust or other contamination which could cause a head crash. Winchester is a code name rather than a brand name, and originated with the early IBM 3340 which had two 30-megabyte volumes; “30-30” was a nickname for a Winchester rifle.
WinCode
A utility that can decode uuencoded files in Windows.
Wind River Systems
A worldwide company based in Alameda, California, which is a supplier of embedded systems and development tools.
window
A division of a computer display screen, which has boundaries and is usually a rectangular area. In a full-featured graphical interface, windows can be opened, closed, and moved around on the screen. The user can control the size and shape of the windows; also windows can be overlapped, and overlapping windows can be brought to the front or sent to the back. The active window is the one in which the user is currently working, and appears in front. Windows can usually be scrolled to view different areas. Different applications or files can be displayed on the screen at the same time in different windows.
window manager
The part of windowing software which controls functions of the windows such as moving, overlapping, resizing, scrolling, displaying menus, etc.
window system
Software that makes it possible for a computer to display windows, such as the X Window System, the Macintosh window system, NeXt, and NeWS.
windowing software
Software that provides an operating system with the capability of displaying windows.
windowing system
An operating system such as Macintosh, Motif, OS/2, RISC OS, Windows, or X Windows that uses windows to display information.
Windows 1
The first version of Microsoft Windows, which came out in 1985. It was able to display tiled windows.
Windows 2
The second version of Microsoft Windows, which improved on Windows 1 by allowing overlapping windows and icons and supporting expanded memory. It was released in 1987. It was later named Windows/286.
Windows 3.0
The first version of Microsoft Windows that gained wide popularity. It is able to manage larger amounts of memory than previous versions, and can run 16-bit DOS and Windows applications. Many applications were developed for Windows 3.0.
Windows 3.1
An improvement on Windows 3.0, which includes multimedia capability, TrueType fonts, and Object Linking and Embedding (OLE). With the Win32s extension, Windows 3.1 can run 32-bit applications. Windows 3.1 is the stand-alone Windows; there is also Windows for Workgroups 3.1.
Windows 3.11
The last upgrade to Windows 3.1.
Windows 95
An operating system with graphical user interface from Microsoft, which can run 32-bit applications. Windows 95 was a major upgrade from earlier versions of Windows up to Windows 3.1, which simply provided a graphical user interface for DOS. Some features of Windows 95 are Plug and Play capability, threading, pre-emptive multitasking, and built-in networking. The user interface has icons and folders similar to Macintosh, and allows the use of long file names. The minimum requirements for a computer to run Windows 95 are an 80386 or Pentium CPU and at least 8 megabytes of RAM.
Windows 98
Microsoft's operating system released after Windows 95. Windows 98 supported new technologies including FAT32, AGP, MMX, USB, DVD, and ACPI. Another new feature of Win98 was the Active Desktop, which integrated the Web browser, Internet Explorer, with the operating system. To the user of Active Desktop, there is no difference between accessing a document local to the user’s hard disk and accessing a document from a Web server on the other side of the world.
Windows ABI
(WABI); Windows Application Binary Interface. A software package from SunSoft that provides Microsoft Windows emulation for UNIX. It translates calls made by Windows applications into X Window calls.
Windows application binary interface
(WABI); Windows ABI. A software package from SunSoft that provides Microsoft Windows emulation for UNIX. It translates calls made by Windows applications into X Window calls.
Windows CE
Microsoft® Windows® CE 2.0 is a 32-bit, Windows-compatible real-time operating system that fills the need for a small, scalable operating system that works in a broad selection of embedded and non-embedded products.
Windows environment
1. An operating system or application program that uses windows to display information. 2.A computer running a version of Microsoft Windows.
Windows for Workgroups
(WFW). A version of Windows 3.1 which is specifically designed to be used with a network.
Windows for Workgroups 3.11
An upgrade to Windows for Workgroups 3.1 which includes 32-bit file access and the ability to send and receive faxes.
Windows Internet Naming Service
(WINS). A program that runs under Windows NT Server which correlates the host name of a computer on a network with its physical IP address, thus making it possible to find computers on other networks.
Windows network
A local area network of computers that all use Windows 95, Windows NT, or Windows for Workgroups.
Windows New Technology
Windows NT. A 32-bit operating system from Microsoft for high-end workstations, servers, and networks. It has built-in networking, pre-emptive multitasking, multi-threading, memory protection, and fault tolerance. It can be used on PCs and other types of computers, including DEC Alpha. Windows NT supports the Unicode character set, which allows more characters than standard ASCII. The minimum requirements for Windows NT are an 80386 processor, and at least 12 megabytes of RAM. Windows NT has become especially popular as a server because of its extra security features.
Windows NT
Windows New Technology. A 32-bit operating system from Microsoft for high-end workstations, servers, and networks. It has built-in networking, pre-emptive multitasking, multi-threading, memory protection, and fault tolerance. It can be used on PCs and other types of computers, including DEC Alpha. Windows NT supports the Unicode character set, which allows more characters than standard ASCII. The minimum requirements for Windows NT are an 80386 processor, and at least 12 megabytes of RAM. Windows NT has become especially popular as a server because of its extra security features.
Windows NT Server
(NTS). The server version of Windows NT, which supports symmetric multiprocessing and online transaction processing for a large number of
users.
Operating system released by Microsoft Corporation in 2001 as a successor to Windows Me. Windows XP is built on the Windows 2000 kernel to ensure greater stability and has a redesigned user interface. It was released in two versions, Windows XP Home version which includes greater home networking capabilities, and Windows XP Professional for office users.
Windows, Icons, Menus, and Pointers
(WIMP); or Windows, Icons, Mouse, Pull-down Menus. A WIMP interface is a graphical user interface such as used in Macintosh, Microsoft Windows, OSF/Motif, NeWS, RISC OS, and the X Window System. The first graphical user interface was developed at Xerox Palo Alto Research Center.
Windows/286
The second version of Microsoft Windows, originally called Windows 2, which improved on Windows 1 by allowing overlapping windows and icons and supporting expanded memory. It was released in 1987.
Windows/386
A version of Microsoft Windows that followed Windows/286, released in 1987. It added the ability to run several applications at a time, by using extended memory.
winkey
A winking face such as ; ) or ;-) (emoticon).
Winmark
A unit of computer performance used in the Winbench tests from Ziff-Davis. Winmarks are used to rate such features as graphics accelerators, disk speed, and disk caching.
WINS
Windows Internet Naming Service. A program that runs under Windows NT Server which correlates the host name of a computer on a network with its physical IP address, thus making it possible to find computers on other networks.
Winsock
Windows Sockets. An implementation of a socket for Microsoft Windows. Winsock provides an interface between Windows applications and TCP/IP, and is used to make network connections. Winsock is built into Windows 95, and there are versions for other operating systems.
Winstone 97
Winstone 97 is a system-level benchmark that measures a PC's overall performance running Windows-based 32-bit applications. Winstone's test suites run actual applications to test the computer's performance.
Wintel
The combination of Microsoft Windows and an Intel CPU.
WinWord
The version of Microsoft Word that is used with Microsoft Windows.
WINZIP
A graphical user interface from Microsoft Windows for PKZIP, including a help resource, which makes it easier to use PKZIP.
wireframe modeling
A computer representation of a three-dimensional image by showing the outlines of all edges in a transparent drawing, as if the object was fashioned with wires. This technique is used in computer-aided design (CAD).
wirehead
A hacker who is an expert with hardware, especially networking components.
Wireless Application Protocol
(WAP). A global standard for developing applications over wireless communication networks.
wireless communications
In computer networking, this term refers to networks that are connected by radio rather than by wires. Wireless communications are enabled by packet radio, spread spectrum, cellular technology, satellites, and microwave towers, and can be used for voice, data, video, and images. Sometimes wireless networks can interconnect with regular computer networks.
Wireless Markup Language
(WML). An XML-based markup language, designed for specifying the content and user interfaces of narrowband wireless devices, such as pagers and cellular phones.
wireless phone
Telephone service that is transmitted without using wires. Examples are cellular mobile phone service and PCS.
wireline
Telephone service that uses wires.
wiring closet
The place where the cables for a network are installed.
Wirth, Niklaus
A Swiss professor, the creator of programming languages Pascal, Modula-2 and Modula-3.
wizard
1. A program utility that works as an interactive guide by walking the user step-by-step through an unfamiliar task. For example, a Word wizard might assist the user in drafting a business letter. 2. An expert hacker or computer programmer. 3. A privileged user on a system, who has powers beyond those of the ordinary user.
wizard mode
A mode in which a user has special privileges on a system; this terminology is particularly used in games and avatar-based chat environments.
WMA
The Windows Media Audio format for digital music, launched by Microsoft as an alternative to the MP3 format. WMA files can be encoded to restrict playback to a certain number of plays, time period, or use by a single PC.
WMF
A file extenstion used for vector images encoded as a Windows metafile.
WML
Wireless Markup Language. An XML-based markup language, designed for specifying the content and user interfaces of narrowband wireless devices, such as pagers and cellular phones.
WMLScript
Based on Wireless Markup Language (WML), WMLScript is similar to JavaScript, but designed for wireless devices. It uses small amounts of memory and CPU power because it does not contain elaborate and unnecessary functions found in some other scripting languages. It is supported by the Wireless Application Protocol (WAP).
WO
Write Once. Refers to storage media such as WORM and CD-R on which data can be written once, but not erased or rewritten.
Wolfram Research, Inc.
The company which developed Mathematica, a program for symbolic mathematics, which was originally a Macintosh program but is now available for many types of computers. The company was founded by Stephen Wolfram.
WOMBAT
Waste Of Money, Brains, And Time.
Word
Microsoft Word. A full-featured word processing program for Macintosh, DOS, and Windows.
word
1. In text, a character or combination of characters appearing between spaces or between a space and a punctuation mark, usually representing a spoken word. 2. The number of bits that can be stored in one CPU register in a computer. The size of a word is usually the width of the data bus. Since most bytes in present-day computers are eight bits, a word is usually a multiple of eight; a common size is two eight-bit bytes (16 bits) or four eightêes (32 bits). Larger computers may have 64-bit words. The size of word that can be transmitted affects the speed of the computer.
Word for Windows
Microsoft Word for use with Microsoft Windows.
Word Pro
A word processing program for Windows from Lotus; it superseded Ami Pro. One feature of Word Pro is that several people can work on the same file at once, via a network. See Lotus Development Corporation
word processing
The preparation of text documents, usually by means of a computer. Word processing is a stage of desktop publishing: the preparation of text, rather than the design or typography. Some features provided by word processing software include word wrap, text editing functions, type styling, page formatting, search and replace, spelling and grammar checking, style sheets, headers and footers, page numbering, sorting, and mail merge.
word processor
1. A computer program used to produce text documents. Examples are WordPerfect, Microsoft Word, Word Pro. 2. A computer which is designed specifically for word processing. Specialized word processor machines have been mostly superseded by personal computers which can perform many functions.
word separator
Any character used to separate words, such as a blank space or punctuation mark.
word size
The number of bits a CPU can process at once; word size is usually the same as the width of the CPU's external data bus, but sometimes is smaller.
word wrap or wordwrap or word-wrap
A feature in most word processing programs and text editors that makes a word bump over to begin the next line when the type reaches the right margin. The type automatically wraps over to the next line without the user having to hit the return key.
WordPerfect
An advanced word processing program from WordPerfect Corporation, originally introduced for Data General minicomputers; now available for DOS, Windows, Macintosh, UNIX, and other computers. Later versions include desktop publishing, fax, email, and spreadsheet functions.
WordPerfect Corporation
The company that developed WordPerfect word processing software and other applications. Originally founded in 1979 in Provo, Utah, as Satellite Software International, the company later became WordPerfect Corporation. It was bought by Novell Inc. in 1994, and then by Corel in 1996.
WordStar
WordStar is a word processing program orginally developed by MicroPro International. WordStar was the dominant word processor for the CP/M operating system, and was adapted to the MS-DOS/PC-DOS platform as well. MicroPro lost market share at an incredible rate in the early to mid 1980's by releasing a very buggy product known as WordStar 2000 to compete with WordPerfect. MicroPro was eventually purchased by SoftKey International, a publisher of low-cost software. SoftKey was in turn purchased the The Learning Company, who was acquired by Mattel. Today, WordStar for DOS is only sold by The Learning Company by special request.
WordTech
The Orinda, California, company that manufactures the Quicksilver compiler.
workaround
A temporary fix or bypass of a problem in a system.
workflow
The scheduling of jobs, or the organization of each part of a project including passing it from one department or individual to another.
workflow management
The automatic routing of a project from one department or individual to another as each step of the project is completed.
WorkForce
An application from Adaptiv Software which helps employers manage information about employees, shifts, and pay schedules, and build labor forecasts.
workforce
1. The workers working in a particular business or activity. 2. The workers potentially available to work.
workgroup
Two or more computer users working together on a project, sharing data and files by means of a network. Groupware is designed for use by workgroups.
working group
(WG). A group of people working on a particular project. This term is often used for groups of people who are developing new technology in computing.
worksheet
A table which displays numbers in rows and columns, used for accounting, budgeting, financial analysis, scientific applications, and other work with figures. Same as spreadsheet.
workstation
1. A one-person computer that is more powerful and faster than most personal computers, and is typically used for graphics, scientific computing, CAD, CAE, and other applications requiring high performance and memory. 2. A terminal in a network, which may have its own processing capability. 3. A terminal or personal computer where one person works.
World Wide Web
(WWW). A hypermedia-based system for browsing Internet sites. It is named the Web because it is made of many sites linked together; users can travel from one site to another by clicking on hyperlinks. Text, graphics, sound, and video can all be accessed with browsers like Mosaic, Netscape, or Internet Explorer. The Web can also be accessed with text-only browsers like Lynx.
World Wide Web browser
A program such as Mosaic, Netscape, Internet Explorer, Lynx, and others that are used to view pages on the World Wide Web.
World Wide Web Consortium
W3 Consortium (W3C); also called W3O. The main body that creates standards for the World Wide Web. Based at the Massachusetts Institute of Technology (MIT), it also produces reference software. Its URL is http://www.w3.org/.
World Wide Web Worm
(WWWW). A search engine for the World Wide Web which can search for keywords in 300,000 documents, and cross-references all the documents in which a particular URL is cited. WWWW provides four types of search databases: citation hypertext, citation addresses (URL), HTML titles and HTML addresses.
Worlds Chat
A three-dimensional, avatar-based chat environment for Windows, made by Worlds Inc.
WorldView
A virtual reality modeling language (VRML) viewer for Windows.
WORM
Write Once, Read Many. Describes a type of storage medium that can be written once only, but read many times; usually refers to optical disks.
worm
A computer program that can make copies of itself, and spreads through connected systems, using up resources in affected computers or causing other damage.
wormhole
A hole in a system's security which is intentionally hidden by designers of the system, often for the purpose of providing access to service technicians or maintenance programmers.
wormhole routing
A way of routing messages by transmitting each part of the message separately, but all along the same route. Each part can be forwarded independently of the rest of the message. This technique of message passing is faster than store-and-forward routing, in which the whole message must be received before it can be transmitted to the next station.
Wozniak, Steve
Co-founder of Apple Computer with Stephen Jobs in 1983. Wozniak invented the Apple II computer.
WPS-8
An early word processor in the 1970s, later called DECmate.
wrist rest
A long rectangular pad that sits on the desk in front of the keyboard, where a typist's wrists can rest while typing. Wrist pads may help prevent repetitive strain injury.
wrist support
A rectangular pad that sits on the desk in front of the keyboard, where a typist's wrists can rest while typing. Wrist pads may help prevent carpal tunnel syndrome.
write
To record data onto a disk, tape, or other storage medium.
write access
Authorization to write to files or update files in a computer.
write cycle
The cycle during which data is written into memory.
write error
An error that occurs while trying to write data to disk or tape. It may be caused by damage to the disk or tape.
write once
(WO). Refers to storage media such as WORM and CD-R on which data can be written once, but not erased or rewritten.
write once CD
Also called CD-R (Compact Disc Recordable). A recordable CD-ROM which can be read by normal CD-ROM drives; data can only be recorded once onto a CD-R, and cannot be changed.
Write Once, Read Many
(WORM). Describes a type of storage medium that can be written once only, but read many times; usually refers to optical disks.
write protection
Various hardware or software methods of preventing data from being written to a disk or other medium.
write-only code
A humorous expression referring to programming code so badly written that no one can understand it.
WSDL
The Web Services Description Language (WSDL) is an XML-based language used to describe the services a business offers and to provide a way for individuals and other businesses to access those services electronically. WSDL is derived from Microsoft’s Simple Object Access Protocol (SOAP) and IBM’s Network Accessible Service Specification Language (NASSL). WSDL replaces both NASSL and SOAP as the means of expressing business services in the UDDI registry.
WSFN
Which Stands For Nothing. A beginning programming language for Atari computers.
WSP
Web Standards Project. An initiative by WWW developers and users to stop fragmentation of the Web, by establishing standards for browsers and encouraging browser makers to follow them.
WWW
World Wide Web. A hypermedia-based system for browsing Internet
sites. It is named the Web because it is made of many sites linked together; users can travel from one site to another by clicking on hyperlinks. Text, graphics, sound, and video can all be accessed with browsers like Mosaic, Netscape, or Internet Explorer. The Web can also be accessed with text-only browsers like Lynx.
WWW browser
World Wide Web browser. A program such as Mosaic, Netscape, Internet Explorer, Lynx, and others that are used to view pages on the World Wide Web.
WWWW
World Wide Web Worm. A search engine for the World Wide Web which can search for keywords in 300,000 documents, and cross-references all the documents in which a particular URL is cited. WWWW provides four types of search databases: citation hypertext, citation addresses (URL), HTML titles and HTML addresses.
WYSIAYG
What You See Is All You Get. An ironic rewording of WYSIWYG.
WYSIWYG
What You See Is What You Get. Refers to the ability of a computer to present an image of a page layout or graphic on its screen that shows how the actual page will look like when it comes out of the printer. Before advanced computer technology made WYSIWYG possible, a typesetter formatting a page would see only unformatted lines of type and coding on the screen, and would have to hope that the copy that came out would look the way it was supposed to.
WYSIWYN
What You See Is What You Need.
WYSIWYP
What You See Is What You Print. Refers to the ability of a computer to display the same colors and resolution on the screen that will come out of the printer. Calibrating the printer and monitor and using a color matching system make it possible to match screen display and finished product.
X
1. Formally, the X Window System; also nicknamed X Windows. A popular window system developed at MIT and used on some workstations. It is often used on UNIX systems and can be run with other major operating systems. With X, users can run applications on other computers in the network while viewing the output on their own screens. The X terminal with keyboard, mouse, and monitor is considered the server and the applications, which may run on the same computer or a different computer, are considered the clients. 2. The CCITT documents that define communication network standards; for example, X.400 – the Message Handling System, and X.500 – Directory Services.
X Bitmap
A black and white bitmap graphics format used by UNIX. Its filename extension is .XBM. In some WWW browsers, the white parts of the image appear transparent, taking the color of the background.
X Pixelmap
An 8-bit, 256 colors, bitmap graphics format used with UNIX and the X Window System.
X protocol
The protocol used by the X Window System for exchanging messages between clients and servers.
X terminal
A terminal which acts as an X server.
X Window System
Also called X or X Windows. A popular window system developed at MIT and used on some workstations. It is often used on UNIX systems and can be run with other major operating systems. With X, users can run applications on other computers in the network while viewing the output on their own screens. The X terminal with keyboard, mouse, and monitor is considered the server and the applications, which may run on the same computer or a different computer, are considered the clients.
X Windows
Formally knows as the X Window System; also called X. A popular window system developed at MIT and used on some workstations. It is often used on UNIX systems and can be run with other major operating systems. With X, users can run applications on other computers in the network while viewing the output on their own screens. The X terminal with keyboard, mouse, and monitor is considered the server and the applications, which may run on the same computer or a different computer, are considered the clients.
x-axis
The horizontal axis, representing width, in an x-y coordinate system or three-dimensional coordinate system.
x-height
The height of a lowercase x. The x-height plus the height of the ascender and descender determines the point size.
X-off
Transmitter off. A code that turns off the transmission of data from a computer to a terminal.
X-on or X-ON
Transmitter on. A code that turns on the transmission of data from a computer to a terminal.
x-y matrix
A two-dimensional matrix, in which the x axis is the horizontal row, and the y axis is the vertical row. Examples are mathematical tables and two-dimensional graphic figures.
x-y-z matrix
A three-dimensional matrix, in which the x axis represents width, the y axis represents height, and the z axis represents depth.
X.25
A standard protocol for packet-switched data networks, published by the International Telecommunications Union, Telecommunications Sector (ITU-TS). The standard specifies the interfaces between data terminal equipment and the packet-switched network, and how data is assembled into packets. An alternative protocol for packet-switched networks is the newer frame relay standard.
X.500
A set of ITU-T standards for online directory services, also called a directory information base (DIB) or white pages. X.500 provides a hierarchical structure and some security features like selective access to certain attributes of a listing.
X/Open
An international consortium of computer product vendors whose purpose is to promote the development of portable applications based on UNIX. This group publishes the X/Open Portability Guide.
x86
A series of microprocessors developed by Intel, used in PCs. See 286, 386, 486, 586, 686.
Xapi-J
A standardized XML (Extensible Markup Language) API (Application Programming Interface) in Java.
Xbase
The generic term for database languages similar to dBASE. Some examples are FoxPro and Clipper.
Xeon
A new Pentium II cartridge introduced by Intel in 1998, designed for use with high performance servers. The Xeon, twice as tall as the Pentium II, fits into new connector called Slot Two. Other improvements are new type L2 cache CSRAM chips, which run at full CPU speed; support for clustered servers; new chip sets 82440GX and 82450NX; possibility of caching up to 8 GB RAM; ability to use up to eight Xeons in one server.
Xerox Corporation's Palo Alto Resea
(Xerox PARC). The research center from which came many important innovations in the computer field, such as some elements of the graphical user interface (the mouse, windows, and icons), laser printers, object-oriented langauges, bitmap graphics, local area networks, and the personal computer itself. Most of these innovations, though discovered at PARC, were not marketed until other companies became interested in them.
Xerox PARC
Xerox Corporation's Palo Alto Research Center. The research center from which came many important innovations in the computer field, such as some elements of the graphical user interface, laser printers, object-oriented langauges, bitmap graphics, local area networks, and the personal computer itself. Most of these innovations, though discovered at PARC, were not marketed until other companies became interested in them.
XFDL
Extensible Forms Description Language. An open protocol for creating, filling in, and reading complex business forms and legal contracts on the Internet and intranets. XFDL, based on XML, was developed because HTML is not suitable for representing auditable business forms. Though a form has both questions and answers, a form in HTML can only store the answers that the user entered. Using XFDL, the form’s questions and answers can be stored in a single file that can then be digitally signed.
xfr
An abbreviation for “transfer”, used in data communications.
XFree86
The free Linux equivalent to the X Window System.
XGA
Extended Graphics Array. A super VGA card from IBM which can provide up to 1024 x 768 pixels and 65,536 colors in its images (resolutions available depend on the combination of XGA card and monitor).
XGML
Text processing software from Software Exoterica Corporation, Ontario. It supports SGML and uses XTRAN, a language for translation and other operations on text. It is available for IBM mainframes, PC, Mac, UNIX, and other systems.
XLF
Extensible Log Format. A log format based on XML, designed to be extensible and universal.
Xlib
X library: The program interface for the X Window System.
XLink
An XML application that expands the way hyperlinks can be used. XLink makes it possible to target a specific section of a document, and adds other options to make linking easier.
XLL
Extensible Linking Language. Specifications for XML linking and addressing mechanisms. XLL has been subdivided into two components: XLink and XPointer. XLink governs how links may be inserted into XML documents, whether they are simple unidirectional hyperlinks as in HTML or more sophisticated two-way, multidirectional, and typed links. XPointer defines a language to be used with XLink for addressing internal elements of XML documents.
XMIT
Transmit.
XML
Extensible Markup Language. A programming language developed by the World Wide Web Consortium; essentially a simplified version of SGML that allows Web developers to create customized tags that will organize and deliver content with more efficiently. XML is a metalanguage, containing a set of rules for constructing other markup languages. By allowing people to make up their own tags, it expands the amount and kinds of information that can be provided about the data held in documents. Some of the advantages are: search engines will be able to zoom in on one particular meaning of a word; new languages can be employed that will allow musical notation and mathematical and chemical symbols to be used as easily as text; e-commerce will become more practical. The World Wide Web Consortium published XML 1.0 in December 1997 www.w3c.org/XML/). Microsoft is a huge proponent of XML, often claiming it will replace HTML and become the next industry standard.
Xmodem
A file transfer protocol, predecessor to Ymodem and Zmodem.
xmosaic
A version of Mosaic for the X Window System.
XMT
Abbreviation for transmit.
XOR
Exclusive OR. An exclusive OR is true if one of the inputs is true, but not both. “A XOR B” means “A or B, but not both.”
XOR gate
A Boolean logic gate used in computer arithmetic. An XOR gate generates a 0 if both the inputs are 0 or if both the inputs are 1. If one of the inputs is 1 and the other is 0 it generates a 1.
Xp orientation
Orientation of a font along the X axis for printing.
xref
Abbreviation for cross-reference.
XRemote
A serial line protocol for the X Window System.
XRN
A Usenet newsreader program for the X Window System.
XSL
Extensible Style Language. A language used to create stylesheets for XML, similar to CSS (Cascading Style Sheets) that are used for HTML. In XML, content and presentation are separate. XML tags do not indicate how they should be displayed. An XML document has to be formatted before it can be read, and the formatting is usually accomplished with stylesheets. Stylesheets consist of formatting rules for how particular XML tags affect the display of a document on a computer screen or a printed page. In XML, different stylesheets can be applied to the same data to hide or display different parts of a document for different users.
XSLT
Extensible Style Language Transformation. It is the language used by .XML style sheets to transfer one form of an .XML document to another .XML form. This transition is extermely useful in e-commerce and e-business, as it serves as a common denominator across many different platforms and varying .XML document coding.
XT
(Extended Technology). The first IBMPC to have a hard disk. It came out in 1983. It had an Intel 8088 microprocessor, 128KB of RAM, and a 10MB hard drive.
xterm
A terminal emulator for X Windows.
XTRAN
A language for translation, matching, and other operations on text.
XVGA
Extended Video Graphics Array. See also VGA.
XView
A toolkit derived from SunView that provides an Open Look user interface for X applications.
XVT
Extensible Virtual Toolkit. An applications development toolkit from XVT Software, Inc., which makes it possible to develop user interfaces for multiple platforms.
xyzzy
A magic word used in the ADVENT adventure game.
y-axis
The vertical axis, representing height, in an x-y coordinate system or three-dimensional coordinate system.
y-punch
A punch in the top row of a Hollerith card.
Y2K
Year 2000. The year that many computers may develop problems because of lack of foresight on the part of programmers. In the 1980s and before, most computer programs were designed to store only the last two digits of the years on all dates. When the Year 2000 comes, these programs will show dates of 00, which may be interpreted the same as 1900. This discrepancy may cause widespread problems, especially in the large computer systems used in government and big industries. For some reason, nobody thought to do something about this problem until the 1990s, and it may be too late. Even though most programs have been updated, it will be difficult to track down all the places the date problem occurs.
YA
Yet Another.
yacc
Yet Another Compiler Compiler. A UNIX compiler used to generate C compilers.
YAFIYGI
You Asked For It, You Got It. Refers to user interfaces which are not WYSIWYG (What You See Is What You Get). With YAFIYGI, the file on the screen may show text and code, but does not show what the printed out copy will look like.
YAHOO
Yet Another Hierarchical Organized Oracle. An online World Wide Web directory, found at http://www.yahoo.com. It includes access to the Alta Vista search engine. Also called Yet Another Hierarchically Officious Oracle.
Yahoo! Pager
Yahoo!'s instant messaging system
Yahooligans!
YAHOO for children.
yay
Yet Another Yacc. An extension of UNIX compiler yacc (Yet Another Compiler Compiler).
Year 2000
(Y2K). The year that many computers may develop problems because of lack of foresight on the part of programmers. In the 1980s and before, most computer programs were designed to store only the last two digits of the years on all dates. When the Year 2000 comes, these programs will show dates of 00, which may be interpreted the same as 1900. This discrepancy may cause widespread problems, especially in the large computer systems used in government and big industries. For some reason, nobody thought to do something about this problem until the 1990s, and it may be too late. Even though most programs have been updated, it will be difficult to track down all the places the date problem occurs.
Yellow Pages
(YP or yp). The former name for Network Information Service (NIC), Sun's client-server protocol for keeping track of user and host names on a network.
Yet Another Compiler Compiler
(yacc). A UNIX compiler used to generate C compilers.
Yet Another Yacc
(yay). An extension of UNIX compiler yacc (Yet Another Compiler Compiler).
YIQ
The image encoding scheme used for color TV and the NTSC video standard. Y is luminance, I is red minus Y, and Q is blue minus Y. Luminance alone gives a black and white or monochrome signal, as in black and white TV. See also YUV.
Ymodem
A file transfer protocol, faster than Xmodem, but not as advanced as Zmodem.
yo-yo
1. A toy which has two thick flat round sides and a peg between them around which is wound a string. The yo-yo goes up and down as the string is wound or unwound. 2. To rapidly switch between being up and down several times (speaking of a computer).
yocto-
The SI prefix meaning 10^-24.
yotta-
The SI prefix for 10^24; or, in binary, 2^80 = 1,208,925,819,614,629,174,706,176
yottabyte
2^80 = 1,208,925,819,614,629,174,706,176 bytes, which is 1,024 zettabytes.
You Asked For It, You Got It
(YAFIYGI). Refers to user interfaces which are not WYSIWYG (What You See Is What You Get). With YAFIYGI, the file on the screen may show text and code, but does not show what the printed out copy will look like.
Your Mileage May Vary
An expression seen next to EPA mileage ratings in car advertisements, which means the buyer may not get the same mileage as the rating. This expression has been adopted by computer users as a disclaimer on free software and in online chat to mean “Your experience may be different.”
Yourdon, Edward
The developer of Yourdon software engineering methodology and publisher of educational and technical books on software engineering.
YP
Yellow Pages, now called Network Information Service. Sun's client-server protocol for keeping track of user and host names on a network.
Yp orientation
Orientation of a font along the Y axis for printing.
YTalk
A chat program that allows multiple users to have conversation online.
YUV
The native signal format for video, in which Y is luminance, U is red minus Y, and V is blue minus Y. To display video on a monitor, the YUV data must be converted to RGB.
YYYY-MM-DD
Year Year Year Year – Month Month – Day Day. The ISO standard formula for writing dates, which avoids the Century Date Change (Y2K) problem.
Z force
A touch screen's sensitivity to pressure.
Z Object Publishing Environment
(ZOPE). A free, open-source web application platform used for building high-performance, dynamic Web sites.
Z shell
(zsh). A UNIX command interpreter.
z-axis
The third dimension (depth), in a three-dimensional coordinate system. The x-axis is the width and the y-axis is the height.
z-fold paper
Continuous paper with holes on the edges, folded like a "z" with each page folded the opposite direction of the page before. It is used in tractor-feed dot matrix printers; after printing, the pages are separated along the perforations and the edge strips are torn off.
Z-mail
A commercial mail user agent for MS-DOS and Unix.
Z3
An early computer from the 1940s.
Z39.50
An ANSI (American National Standards Institute) search and retrieval protocol used by WAIS (Wide Area Information Service).
Z80
An 8-bit microprocessor from Zilog with a clock speed of 2 MHz, used in many personal computers with the CP/M operating system.
Z8000
A 16-bit microprocessor from Zilog Corporation.
zap
1. To hit with a sudden, concentrated force. The expression probably originates from comic books where characters are “zapped” with lasers, electricity, or other forces, sometimes even magical forces. Zapping is indicated by a balloon with jagged lines around it and the word ZAP! in big letters. 2. When things get zapped in comic books they often are killed or destroyed; but in computer jargon, zapping can refer to various processes used to fix things. For example, to “zap the PRAM” means to reset it.
ZBR
Zone Bit Recording (also called zone constant angular velocity). Ordinarily, data is recorded on a magnetic disk on concentric tracks that each hold the same number of bits. When the disk rotates at constant speed (constant angular velocity), the tracks near the periphery of the disk move faster than the tracks near the center. Therefore, the outside tracks must be physically larger in order to hold the same amount of data as the inner tracks; they also have less recording density. Zone bit recording is a method of storing data on a disk in which the disk rotates at constant angular velocity, but the outer tracks can have higher recording density than on a conventional disk, thus making it possible to store more data. This is achieved by dividing the disk into concentric zones and changing the clock rate as the read/write head moves from one zone to another.
ZCAV
(Zone Constant Angular Velocity; also called zone bit recording). Ordinarily, data is recorded on a magnetic disk on concentric tracks that each hold the same number of bits. When the disk rotates at constant speed (constant angular velocity), the tracks near the periphery of the disk move faster than the tracks near the center. Therefore, the outside tracks must be physically larger in order to hold the same amount of data as the inner tracks; they also have less recording density. Zone constant angular velocity is a method of storing data on a disk in which the disk rotates at constant angular velocity, but the outer tracks can have higher recording density than on a conventional disk, thus making it possible to store more data. This is achieved by dividing the disk into concentric zones and changing the clock rate as the read/write head moves from one zone to another.
ZD Net
An electronic information service provided by Ziff-Davis Interactive, which was formerly called ZiffNet. ZD Net has a large library of downloadable shareware and freeware, plus product reviews, computing advice, forums, and email. ZD Net includes the former PC Magnet and ZMac.
ZDBOp
Ziff-Davis Benchmark Operation. The division of Ziff-Davis, Inc. that develops the benchmark programs used by Ziff-Davis publications, including BatteryMark, BrowserComp, MacBench, NetBench, ServerBench, WebBench, WinBench, and Winstone.
ZDigit II
This device enables older notebooks with screens that turn off automatically when not in use to run the BatteryMark test by utilizing a motor and a lever to tap a keyboard key (preferably the spacebar) every 15 seconds. The BatteryMark test cannot perform its checks with an unlit notebook screen, hence the ZDigit II becomes important as it is continually taps a key to keep the screen from shutting down. NOTE: ZDigit II devices are only needed on old notebooks that do not have updated BIOS that allow them to keep their screens lit even when not in use.
zepto-
The SI prefix meaning 10^-21.
zero
0; ASCII character 48. The arithmetic symbol for absence of quantity or magnitude.
Zero Insertion Force socket
(ZIF socket). A special socket for plugging in integrated circuits easily. The socket can be opened with a small lever or screw; the chip is dropped in, then the socket is closed.
zero out
1. To set to zero. 2. To erase.
zero punch
In a Hollerith card, a punch that is in the third row from the top.
zero wait state
The execution of instructions or transfer of data with no delay (wait state) to allow time for slower memory chips or external devices to respond. See wait state.
zero-content
Having no content; refers to a communication that doesn't really communicate anything, such as a wordy speech that has no substance.
zerofill
To fill up empty storage locations with zeroes (0).
zeroize
To fill up unused storage locations with zeroes (0).
zeroth
First, in an enumeration that begins with zero. Zero-based numbering is often used in computer programming.
zetta-
The SI prefix for 10^21; or, in binary, 2^70 = 1,180,591,620,717,411,303,424.
zettabyte
2^70 = 1,180,591,620,717,411,303,424 bytes, which is 1024 exabytes.
ZIF socket
Zero Insertion Force socket. A special socket for plugging in integrated circuits easily. The socket can be opened with a small lever or screw; the chip is dropped in, then the socket is closed.
Ziff-Davis Benchmark Operation
(ZDBOp). The division of Ziff-Davis, Inc. that develops the benchmark programs used by Ziff-Davis publications, including BatteryMark, BrowserComp, MacBench, NetBench, ServerBench, WebBench, WinBench, and Winstone.
Ziff-Davis, Inc.
The publisher of well-known computer magazines including MacUser, MacWeek, PC Magazine, PC/Computing, and PC Week. Ziff-Davis also has an online service called ZD Net (formerly ZiffNet).
ZiffNet
(Now called ZD Net). An electronic information service provided by Ziff-Davis Interactive, which has a large library of downloadable shareware and freeware, plus product reviews, computing advice, forums, and email.
zigzag-fold paper
Continuous paper with holes on the edges, folded in zigzag fashion with each page folded the opposite direction of the page before. It is used in tractor-feed dot matrix printers; after printing, the pages are separated along the perforations and the edge strips are torn off.
ZIL
Zork Implementation Language. A programming language used for Infocom games.
Zilog
A microprocessor manufacturer.
zinc air
A rechargeable battery that is more efficient than the older nickel cadmium and nickel metal hydride batteries, and does not have memory effects. See nickel cadmium and nickel metal hydride.
zine
An online magazine, also called ezine or e-zine, for electronic magazine.
zip
To compress a file using PKZIP, ZipIt, gzip, or other compatible archiver.
Zip disk
A 3.5″ removable cartridge used with the Iomega Zip drive. Zip disks can store 25MB or 100MB, and are used to back up data or transfer data from one computer to another.
Zip drive
A small, lightweight, portable disk drive from Iomega, which uses 100-megabyte 3.5″ removable cartridges.
zip file
A file which has been compressed with PKZIP or compatible software. Zip files are indicated by the .ZIP filename extension, and can be unpacked with PKUNZIP or UnZip.
zipperhead
A person who has a closed mind. This expression is said to have originated at IBM.
Zmodem
A file transfer protocol which transmits data between modems in blocks of 512 bytes. It is fast because it does not wait for positive acknowledgement (ACK) after each block of data, but will resend a block if it receives a negative acknowledgement (NAK). If a file transfer is interrupted, Zmodem can resume the transfer later and send only the part of the file that was not yet sent, which can save a lot of time. Zmodem is an advancement over Xmodem and Ymodem.
zone bit recording
(ZBR; also called zone constant angular velocity). Ordinarily, data is recorded on a magnetic disk on concentric tracks that each hold the same number of bits. When the disk rotates at constant speed (constant angular velocity), the tracks near the periphery of the disk move faster than the tracks near the center. Therefore, the outside tracks must be physically larger in order to hold the same amount of data as the inner tracks; they also have less recording density. Zone bit recording is a method of storing data on a disk in which the disk rotates at constant angular velocity, but the outer tracks can have higher recording density than on a conventional disk, thus making it possible to store more data. This is achieved by dividing the disk into concentric zones and changing the clock rate as the read/write head moves from one zone to another.
zone constant angular velocity
(ZCAV; also called zone bit recording). Ordinarily, data is recorded on a magnetic disk on concentric tracks that each hold the same number of bits. When the disk rotates at constant speed (constant angular velocity), the tracks near the periphery of the disk move faster than the tracks near the center. Therefore, the outside tracks must be physically larger in order to hold the same amount of data as the inner tracks; they also have less recording density. Zone constant angular velocity is a method of storing data on a disk in which the disk rotates at constant angular velocity, but the outer tracks can have higher recording density than on a conventional disk, thus making it possible to store more data. This is achieved by dividing the disk into concentric zones and changing the clock rate as the read/write head moves from one zone to another.
Zoo
A compression program for UNIX, DOS, and other platforms, available as freeware.
zoom
A feature in many applications that allows the user to magnify a small area of the file (as if moving in closer: zoom in) or view more of the page with less detail (as if moving farther away: zoom out). The amount of zoom is usually shown as a percentage (25% size, 200% size) or ratio (2:1 means magnified to twice normal size; 1:2 means reduced to 1/2 size).
zoom box
A little box in the upper right corner of the window in a Macintosh file. Clicking once on the zoom box will make the window enlarge to full size; clicking again will make the window return to its smaller size. The Windows equivalent is the Maximize and Restore commands.
zoom in
A feature in many applications that allows the user to magnify a small area of the file, as if moving in closer. The amount of zoom is usually shown as a percentage (200% size) or ratio (for example, 2:1 means twice normal size).
zoom out
A feature in many applications that allows the user to view more of the page with less detail, as if moving farther away. The amount of zoom is usually shown as a percentage (25% size, 50% size) or ratio (for example, 1:2 means reduced to 1/2 size).
Zoomer
A personal digital assistant from Casio.
ZOPE
Z Object Publishing Environment. A free, open source Web application platform used for building high-performance, dynamic Web sites.
Zork
An early computer fantasy game which was the basis for The Zork Trilogy (from Infocom) and the game Dungeon.
Zork Implementation Language
(ZIL). A programming language used for Infocom games.
zorkmid
A unit of currency in Zork and now in some other computer fantasy games.
zsh
Z shell. A UNIX command interpreter.
Zterm
A Macintosh shareware program that provides terminal emulation, ANSI support, and a phonebook. It was the first Mac program to provide Zmodem FTP, and also supports Xmodem and Ymodem.
Zworykin, Vladimir K.
A Russian-born American (1889-1982) who is called the father of television. He patented the iconoscope, predecessor of the television camera, and the kinoscope, which became the television tube. He demonstrated the first practical model of a television in 1938.
Zydeco
A Java-based browser and development environment for XML.
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should be your focus in the first round. The different types of
defensive football positions are:. I guess
a handful of suspensions was enough to satisfy the
NCAA.
Their goal was to establish a statewide coalition between the insurance industry, law enforcement officials and other criminal justice agencies to implement vehicle theft reduction strategies.
Pickup trucks and sport utility vehicles are heavily targeted because they are easy to crawl under.
Dealers must provide consumers with any other advertised rebates or discounts
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