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There are currently 6775 names in this directory
-endian
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.

680x0
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.

A:
The A: drive, the first drive in a computer or on a network. It can be a diskette or hard disk drive.

A/D converter
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.

A/UX
A version of UNIX developed by Apple Computer for the Macintosh.

AA
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.

absolute pathname
A pathname that is defined in relation to the root directory.

absolute 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 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.

Abstract Windows Toolkit
(AWT). A Java application programming interface that allows programmers to develop Java applications having windows, scroll bars, and other components of a 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 (VM).

AC
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's chipset 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.

accelerator board
A printed circuit board added to the computer that replaces the central processing unit with a faster one.

accelerator card
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.

access concentrator

access control
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.

access rights

access time
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 UNIX workstation, 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.

Active Desktop
Microsoft's integration of Windows desktop for Windows 95/98 and Windows NT with Microsoft's Internet Explorer Web browser (4.0 and later) where users can access local and remote information from a single location.

Active Directory
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 Microsoft Internet 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.

ActiveMovie
A Microsoft video application programming interface providing online and desktop multimedia tools.

ActiveX
ActiveX is a model for writing programs so that other programs and the operating system can call them. ActiveX technology is used with Microsoft Internet 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 software application as COM objects so that certain tasks can be "automated" that are normally selected from menus.

ACTOR
An object-oriented programming language for Microsoft Windows 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 browser caching. 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.

ADABAS
A relational database system from Software AG, used for IBM mainframes, UNIX, VAX, and OS/2.

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 network bridge 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 network software 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.

ADCCP
Advanced Data Communications Control Procedure. A communications protocol used by the American National Standards Institute.

ADDMD
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 Internet protocol 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.

ADLC
Asynchronous Data Link Control. See asynchronous transmission.

ADMD
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.

administrative domain
(AD). Defined in RFC 1136. On the Internet, a group of networks, hosts, and routers operated by the same organization.

Administrative 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.

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.

Advanced Interactive eXecutive
(AIX). IBM's version of UNIX.

Advanced Memory Management Architecture
(AMMA) Strategies for providing sufficient memory to all the processes in a computer system, performed by the memory management unit (MMU).

Advanced Micro Devices, Inc.
(AMD). A U.S. manufacturer of integrated circuits, microprocessors, memory, and other computer products.

Advanced Mobile Phone Service
(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-bit RISC microprocessors for computing, games, multimedia, and many other uses. They are energy-efficient and economical.

Advanced SCSI Programming Interface
(ASPI). An interface from Adaptec that allows application programs to access SCSI hardware.

Advanced Technology Attachment
(ATA). The specification for IDE interface.

Advanced Technology Attachment Packet In
(ATAPI). An interface used to connect CD-ROMs, tape drives, and optical disks with the computer.

Advanced WavEffects
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 Macintosh operating system, the AFE utility program allows the Mac to read and record data files from a floppy disk formatted for use on a PC.

AFP
AppleTalk Filing Protocol. An AppleTalk client/server protocol.

After Dark
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's chipset 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.

AIC
AIXwindows Interface Composer (IBM).

AIFF
(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.

AL
Assembly Language. The language in between machine language and high-level programming languages.

Al-Khawarizmi
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.

Aldus
Creator of the PageMaker page layout program for Macintosh, a milestone in desktop publishing; now part of Adobe Systems.

Aldus Pagemaker
The first desktop publishing program, originally designed for Macintosh, now also available for PC.

Aldus Persuasion
A desktop presentation program for Mac from Adobe Systems, Inc.

alert
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 Web browser 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 UNIX operating 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.

Amiga-DOS
Amiga Disk Operating System. See Amiga and Disk Operating System.

AML
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 UNIX software.

angle brackets
The Keyboard symbols <>. Angle brackets are commonly used to enclose HTML tags and other codes.

angstrom
One 10-billionth of a meter. See also A.

ANI
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.

annoybot
An Internet Relay Chat (IRC) bot whose sole function is to send silly or annoying messages.

www.anonymizer.com.

anonymous FTP
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.

American National Standards Institute. 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 Standards Organization (ISO) and the International Electrotechnical Commission (IEC). ANSI standards are voluntary. ASCII is an ANSI character set.

ANSI character set
The ANSI (American National Standards Institute) extended character set used with Microsoft Windows. 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.

ANSI terminal
A display terminal which follows ANSI (American National Standards Institute) standard terminal language commands.

anthrobotics
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.

AOE
Application Operating Environment (AT&T).

>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.

AOL Instant Messenger
(AIM). The instant messaging program of America Online.

aol.com
The Internet domain address for America Online. www.aol.com

AOW
Asia and Oceania Workshop. One of three regional OSI Implementors Workshops. See OIW and EWOS.

APA
1. Adaptive Packet Assembly 2. Application Portability Architecture. DEC portable applications software.

Apache
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 workstation networking. It became a division of HP in 1989.

apostrophe
ASCII character 39: ' . Also called single quote.

app
Abbreviation for application program.

APPC
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 Newton personal 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.

Apple Newton
A personal digital assistant (PDA) made by Apple Computer.

Apple Open Collaboration Environment
(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 network protocol 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.

AppleTalk Filing Protocol
(AFP). An AppleTalk client/server protocol.

application
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-end databases, 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.

architecture
The design of a computer, software, or network.

Architecture Neutral Distributed Format
(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 link protocol 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.

Argus Clearinghouse
See The Argus Clearinghouse.

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).

arithmetic logic unit
(ALU). 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.

ARM
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.

Artisoft, Inc.
Providers of the LANtastic networking products.

ARTS
Asynchronous Remote Takeover Server.

ARTT
Asynchronous Remote Takeover Terminal.

AS/400
Application System/400. A family of IBM minicomputers designed primarily for business applications.

AS3AP
ANSI SQL Standard Scalable And Portable.

AS400
See AS/400.

ascender
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.

ASR
Automatic Speech Recognition.

assembler
A program that converts assembly language into machine language.

assembly code
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.

assembly language
(AL). The language in between machine language and high-level programming languages. Each assembly language statement corresponds to one machine language instruction.

Association Control Service Element
(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.

Association Francaise des Utilisateurs d
(AFUU). The French Association of Unix Users.

Association of C and C++ Users
(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.

Asymmetric Digital Subscriber Loop
Variant of Asymmetric Digital Subscriber Line (ADSL).

ASYNC
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 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.

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&amp;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 UNIX operating 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.

Attached Resource Computer Network
(ARCNET). 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 cables. ARCNET is a data link protocol and uses the token passing access method.

attachment
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.

attack
An attempt to violate computer security.

atto-
The SI prefix meaning 10^-18.

ATX
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 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.

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.

Authorware Professional
A multimedia authoring tool from Macromedia, which can be used with Windows and Macintosh.

auto answer
(AA). Some modems can be set up to accept telephone calls and automatically establish a connection; this ability is called auto answer.

auto dial
The ability of some modems to dial the telephone number of another computer and make a connection.

autobaud
Automatic baud rate detection.

AutoCAD
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.

AutoLISP
A version of LISP used in AutoCAD.

automata
(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.

autonomous internet
A group of gateways that are under the same administrative authority and use a common Interior Gateway Protocol (IGP).

autoresponder
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.

B-)
An emoticon for glasses or sunglasses.

B-ISDN
See BISDN.

B:
The second floppy disk drive in a PC.

B2B e-commerce
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.

Baby AT
A motherboard used in many PCs, smaller than the original Advanced Technology(AT) motherboard.

back door
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.

bang
Exclamation point: ! (ASCII 33).

bang on
To stress-test hardware or software.

bang path
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.

Bank Internet Payment System
(BIPS). A protocol for securely sending payment instructions to banks over the Extensible Markup Language (XML) standard. The Bank Internet Payment System is a project of The Financial Services Technology Consortium (FSTC).

bar chart
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 IBM PCs 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.

Basic Rate Interface
(BRI). Basic ISDN service at 128 kbps.

Basic Stamp
A tiny computer that can be programmed in Basic, used by robotics hobbyists for a robot brain. It contains a PIC microcontroller.

Basic Telecommunications Access Method
(BTAM). IBM communications software used in some mainframe computers.

BASM
Built-in ASseMbler.

bastion host
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.

BCPL
Basic Computer Programming Language.

Be Inc
Be Inc. is a software developer of the BeOS and the BeIA Operating Systems (OS). The BeOS is an OS designed for a personal computer desktop platform, whereas the BeIA (IA stands for Information Applicance) is an OS specifically designed for Internet appliances. Be Inc. was formed in 1990 by Jean-Louis Gassée.

BeBox
This is a machine Be Inc. revealed on October 3, 1995. Jean-Louis Gassée, the CEO of Be Inc. and former employee of Apple Computers, unveiled it in the hopes of attracting users to its low-cost design and high-tech capabilities.

Because It&#039;s Time Network
(BITNET). An academic computer network originally connecting IBM mainframes 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.

Bernoulli drive
A removable hard disk drive made by Iomega Corporation.

Bit Error Rate.

Bertrand Russell
(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.

BFF
Binary File Format (IBM).

BGP
Border Gateway Protocol. An Exterior Gateway Protocol (EGP) for routing within autonomous systems, defined in RFC 1267 and RFC 1268.

BHTML
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.

BIND
Berkeley Internet Name Domain.

BinHex
A format in which Macintosh binary 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 domain protocol 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 IBM PCs and PC-compatibles, which handles all input-output functions.

BIPS
1. Billion Instructions Per Second. 2. Bank Internet Payment System. A protocol for securely sending payment instructions to banks over the Internet and for processing the payment instructions. BIPS instructions conform to the Extensible Markup Language (XML) standard. The Bank Internet Payment System is a project of The Financial Services Technology Consortium (FSTC).

birds of a feather
(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 narrowband ISDN. 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 IBM mainframes 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 8265">software products.

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 coaxial Ethernet 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.

BNS
Backbone Network Service. See backbone.

BNU
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.

board
A slice of insulating material with electronic circuits on one or both sides. See circuit board, expansion board, sound board, motherboard.

BoB
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 Web browsers. 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 Web browsers. 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.

Boolean operators
AND, OR and NOT. See also Boolean algebra.

Boolean query
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.

boot disk
A disk that is used to start a computer.

boot drive
The drive that contains the operating system and is used to boot the computer.

boot up
To load a computer’s operating system.

boot virus
A virus that infects a computer when the computer is booted from an infected disk. A boot virus may make it impossible to start the computer.

boot-up
The process of loading the operating system on a computer; also called boot.

bootable CD
A CD that can be used to boot (start up) the computer.

bootable disk
A disk that contains a loadable operating system and can be used to boot (start up) the computer.

bootleg software
Illegally copied software.

BOOTP
BOOTstrap Protocol. A TCP/IP protocol 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."

BOOTstrap Protocol
See Bootstrap Protocol.

Bootstrap Protocol
(BOOTP). A TCP/IP protocol used to enable a diskless workstation to find its own logical IP address at startup.

bootup
See boot-up.

BOPS
Billion Operations Per Second.

Border Gateway Protocol
(BGP). An Exterior Gateway Protocol (EGP) for routing within autonomous systems, defined in RFC 1267 and RFC 1268.

Borland International, Inc.
A Scotts Valley, California software company which is known for Turbo Pascal, Turbo C, Turbo Prolog, and Borland C++. Borland acquired the dBASE database 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.

Bpi
Bytes per inch.

bpp
Bits per pixel. See bit depth.

BPR
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.

Bps
Bytes per second.

BR
Baud Rate.

bR
Bit Rate.

braces
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 coaxial Ethernet 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 network carriers 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 narrowband ISDN. 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&#039; 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.

browser
A client program that allows users to read hypertext documents on the World Wide Web, and navigate between them. Examples are Netscape Navigator, Lynx, and Microsoft Internet Explorer. Browsers can be text-based or graphic.

browser caching
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 UNIX software and networking products developed at the University of California at Berkeley.

BSD/OS
A commercial version of BSD UNIX, from BSDI (Berkeley Software Design, Inc.). It is an operating system for the 386, 486, and Pentium.

BSDI
Berkeley Software Design, Inc. The company responsible for BSD/OS, a commercial operating system based on BSD UNIX (technology from the University of California at Berkeley).

BSML
Bioinformatic Sequence Markup Language. A proposed public domain protocol 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 Human Genome Research Institute.

BSYNC
Binary SYNchronous Communications (Protocol).

BTAM
Basic Telecommunications Access Method. IBM communications software used in some mainframe computers.

BTOA
Binary to ASCII.

bubble jet
The ink jet printer technology used by Canon.

buffer
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.

bus bridge
A device that connects two busses together.

bus mouse
A mouse that is plugged into an expansion board rather than a serial port.

business machine
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.

business process reengineering
See Business Process Re-engineering.

Business Software Alliance
(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.

Byte
A computing magazine. See also byte

Byte Information Exchange
(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&T Bell 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.

C shell
(csh). A command line interpreter shell and script language for UNIX.

C:
The primary hard disk in a PC.

c/s
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&amp;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&T Bell 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.

caching
Storing data in a cache.

CAD
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.

cancer
In computer slang, a deadly virus.

candela
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 dynamic RAM cells 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.

carrierless amplitude and phase modulati
(CAP). AT&T's modulation technology for ADSL (Asymmetric Digital Subscriber Line).

cartridge
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.

cathode
The electrode of the cathode ray tube which emits electrons, which flow to the positively charged anode. See cathode ray tube.

cathode ray tube
(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.

cc
A UNIX command to compile a C program.

www.ccianet.org

CCIRN
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.

CD burner
A program for writing to a CD or CD-ROM.

CD formats
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.

CD-WO
Compact Disc - Write Once.

CD+G
Compact Disc plus Graphics.

CDA
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.

cdda2wav
A CD ripper and sampling utility.

CDDB
(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-ring network similar to FDDI, but it uses copper cable, and is limited to distances of 50 to 100 meters.

CDF
Channel Definition Format. An application of eXtensible Markup Language (XML) designed to be used with push technology.

CDFS
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.

Cello
A World Wide Web browser that runs under Microsoft Windows.

CellPhimportance
Pronounced self-importance. 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.

Cerfnet
An Internet Service Provider in San Diego, California, U.S.A.

CERN
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 640x200 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.

chained list search
Searching using a chained list.

Challenge-Handshake Authentication Proto
(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.

Channel Definition Format
(CDF). An application of eXtensible Markup Language (XML) designed to be used with push technology.

channel latency
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.

character rotation
The alignment ocharacters in relation to the baseline.

character set
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.

character string
A group or sequence of characters.

character-based interface
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.

CHAt
Conversational Hypertext Access technology (Internet).

chat
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.

Chicago
1. A bitmap typeface. 2. The code name for Microsoft Windows 95 during development.

chiclet keyboard
A keyboard with small, square keys.

chief information officer.
(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.

chkdsk
A DOS command meaning "Check disk space".

choke route
The part of a firewall which isolates an internal network from the Internet.

choose
To pick a command from a pull-down menu.

Chooser
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.

ciphertext
Text that is encrypted, as opposed to plaintext.

ciphertext-only cryptanalysis
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.

circumflex
ASCII character 94: ^ .

Cisco Systems, Inc.
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.

client server
See client/server.

client-client-server
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.

colon
ASCII character 58: : .

color bits
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 640x200 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.

comma
ASCII character 44: , .

comma-separated values
(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&#039;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.

Common Management Information Protocol
(CMIP). The OSI protocol for network management.

communication line adapter
(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 &amp; 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 PC RAM, 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.

Corporation for Research and Educational
(CREN). A corporation formed by the merging of BITNET (Because It’s Time Network) and CSNET (Computer+Science Network).

corrupted file
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.

CPP
C Plus Plus, or C++. A programming language.

CPS
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.

CRM
See Customer Relationship Management (CRM).

CROM
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.

csh
C shell. A command line interpreter shell and script language for UNIX.

CSLIP
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.

data item
One unit of data stored in a field.

data library
A directory on a server that contains files for downloading.

data link
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.

DAV
Digital Audio Video.

DB
Database. (Also see dB(decibel)).

dB
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.

DD-MM-YY
DayDay MonthMonth YearYear.

DD-MM-YYYY
DayDay MonthMonth YearYearYearYear.

DDB
Device Dependent Bitmap.

DDC
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.

del
A DOS command to delete a file.

DEL
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.

Designer
A Windows draw program by Micrografx, Inc.

DesignWave
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.

deskew
To undo a skew command.

DeskJet
A line of ink-jet printers from Hewlett Packard for PCs.

desktop
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.

DeskWriter
A line of inkjet printers for Macintosh from Hewlett Packard.

destination
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).

df
A UNIX command meaning "Check disk space".

DHCP
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.

DILLIGAD
Do I Look Like I Give A Darn?.

DIMM
Dual Inline Memory Module. A way of adding RAM to the computer. DIMMs normally have 168 pins. See also SIMM (Single Inline Memory Module).

dimmed letters
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.

DirectDraw
A Windows 95 graphics display system.

Director
A multimedia authoring program from Macromedia, available in Windows and Macintosh versions.

Directory Access Protocol
(DAP ). In an X.500 directory system, the protocol used in communications between a Directory User Agent (DUA) and a Directory System Agent (DSA).

directory client agent
(DCA). The agent used to search for names and addresses in an X.500 directory.

directory information base
(DIB). An X.500 directory or online white pages.

Directory Information Tree
(DIT). The directory tree representing information objects in the OSI X.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.

disassembler
A program that converts machine code back into assembly code.

disc
A device used to transport and store information between computers. See diskette.

Discrete Multitone
(DMT). An ANSI-standard modulation technique used with ADSL (Asymmetric Digital Subscriber Line).

discretionary hyphen
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 OSI X.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.

DMT
Discrete Multitone. An ANSI-standard modulation technique used with ADSL (Asymmetric Digital Subscriber Line).

DMY
Day Month Year.

DN
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 IBM PCs, 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.

Dual Inline Memory Module
(DIMM). A way of adding RAM to the computer. DIMMs normally have 168 pins. See also SIMM (Single Inline Memory Module).

dual mode
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.

DVMRP
Distance Vector Multicast Routing Protocol (Internet).

Dvorak keyboard
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 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.

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.

embedded link
A hyperlink in the middle of a line of text.

embedded object
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.

EOF
End Of File.

EOJ
End of Job.

EOL
1. End Of List. 2. End of Line.

EOM
End of Message.

EOP
End Of Program.

EOR
Exclusive OR (See also XOR).

EOT
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.

Ethernet meltdown
A network meltdown on an Ethernet.

EtherTalk
Software from Apple Computer that adapts a Macintosh to an Ethernet network.

ETX
End of text.

Eudora
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.

European Workshop for Open Systems.
(EWOS). The OSI Implementors Workshop in Europe.

EurOpen
Formerly European UNIX Users Group (EUUG).

EUUG
European UNIX Users Group. Now called EurOpen.

EVE
Extensible VAX Editor.

even parity
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).

exajoule
A quintillion (10^18) joules. See exa-.

Excel
A popular spreadsheet program from Microsoft, available for Macintosh and PC.

excessive cross posting
(ECP). Posting the same message to many Usenet groups, including those where the subject is not relevant; also called spamming.

excessive mass posting
(EMP). Excessive posting to many Usenet groups at once, including to groups where the subject is not relevant; also called spam.

excessive multiple posting
(EMP). Excessive posting to many Usenet groups at once, including to groups where the subject is not relevant; also called spam.

exchange
The first three digits of a local phone number, not including area code.

Excite
An Internet search engine.

excl
Exclamation point, ASCII character 33.

exclamation point
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.

expansion board
A printed circuit board, also called an expansion card, which can be plugged into the computer's expansion slot to add a new feature; for example, a expansion bus
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/).

Extensible Style Language
(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 NT database 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.

FIPS
Federal Information Processing Standard.

Fire Wire
See FireWire.

firewall
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&#039;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); 680x0 (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/ .

HotJava
A World Wide Web browser from Sun Microsystems that can execute Java applets.

http://www.hp.com.

HPA
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.

iBCS
Intel Binary Compatibility Specifications (Intel).

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.

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).

ICAS
Intel Communicating Applications Specifications (Intel).

ICB
Internet Citizens Band.

ICCP
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, softwar