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There are 493 names in this directory beginning with the letter P.
P-mail

Regular postal service or snail mail.

P.O.D.

Piece Of Data (rather than a programming instruction).

P5

Pentium. The Intel high-performance microprocessor introduced in 1993, also called 586 or 80586. It is about twice as fast as the 486.

P6

The Pentium Pro. Successor to the Pentium microprocessor; also called 686 or 80686. The P6 has internal RISC architecture and a CISC-RISC translator. It is faster than the Pentium for 32-bit software but slower for 16-bit software.

PA-RISC

A RISC chip used in HP minicomputers and workstations.

PABX

Private Automatic Branch Exchange. A private automatic telephone exchange that allows calls within the exchange and also calls to and from the public telephone network.

pack

To store data in compressed form in such a way that the data can be restored to its original form (unpacked).

packaged software

An application program or collection of programs developed to meet the needs of a variety of users, rather than custom designed for a specific user or company. Packaged software is sold to the general public.

Packard Bell Electronics, Inc.

A leading U.S. computer vendor based in Sacramento, California. Packard Bell originally started in 1926 as a radio manufacturing company, and now markets complete computer systems in major retail chains.

packed decimal format

A means of storage in which each byte holds two decimal digits (four bits per digit), except the rightmost byte which contains one digit and the sign (+ or -). See unpacked decimal format.

packet

A unit of data formatted for transmission on a network. Data is broken up into packets for sending over a packet switching network. Each packet has a header containing its source and destination, a block of data content, and an error-checking code. All the data packets related to a message may not take the same route to get to their destination; they are reassembled once they have arrived.

packet assembler / disassembler

(PAD). A hardware device that makes it possible for a data terminal not set up for packet switching to use a packet switching network. It assembles data into packets for transmission, and disassembles the packets on arrival so they can be used.

packet cellular

Packet transmission of data via cellular network.

packet driver

Local area network software that divides data into packets for sending on the network, and reassembles the data into its original form when it arrives at its destination.

packet internet groper

(PING). A program used to test whether a particular network destination is online, by sending an Internet control message protocol (ICMP) echo request and waiting for a response. (Also called packet internet gopher).

packet overhead

On a packet-switched network, the time it takes to transmit the extra bytes of formatting information included with each packet, and to assemble and disassemble the packets. The total transmission time includes packet overhead as well as the time it takes to transmit the raw data.

packet radio

(PR). The transmission of data packets between computers by means of amateur radio. Packet radio provides electronic mail, BBS service, chat, file transfer, and games.

packet switch node

(PSN). A dedicated computer which routes packets for a packet-switched network.

packet switching

A technology for sending packets of information over a network. Data is broken up into packets for transmission. Each packet has a header containing its source and destination, a block of data content, and an error-checking code. All the data packets related to a message may not take the same route to get to their destination; they are reassembled once they have arrived. The international standard for packet switching networks is X.25.

packet-switched network

A network that in which a temporary connection is established between points for the transmission of data in the form of packets.

packets per second

(PPS). The measurement of transmission speed in a local area network.

packing density

The number of electronic components on a given area of an integrated circuit.

PackIt

A Macintosh compression format used to pack together a collection of small files before transferring them.

pad

To fill unused portions of a data structure with dummy data such as zeros, blanks, or nulls.

PAD

Packet Assembler / Disassembler . A hardware device that makes it possible for a data terminal not set up for packet switching to use a packet switching network. It assembles data into packets for transmission, and disassembles the packets on arrival so they can be used.

pad character

A dummy character which is used to fill up space or time while some operation is performed.

padding

Dummy data used to fill unused portions of a field, such as blanks or zeros.

PADtalk

A programming language used with HyperPAD.

PAGE

A computer language used for typesetting.

page

1. A piece of paper that can have text or graphics printed on it to convey information; a collection of pages is bound together to make a book, magazine, report, etc. 2. The electronic equivalent of a paper page. Word processing programs, desktop publishing programs, etc., can be divided into pages; each page on the computer will form one paper page if the file is printed. 3. In virtual memory, a block of memory that has a virtual address and can be accessed at one time. 4. In videotex, a transmitted frame. 5. To send a message to someone whose location is not definitely known, usually via a loudspeaker announcement or a beeper.

page break

1. In a document, the place where a page ends and a new page begins. A word processor will automatically insert a page break after a certain number of lines; or the user can enter a command to put a page break in a particular place. 2. A code that tells the printer where to end a page.

page description language

(PDL). A language that describes to the printer how to print a page and how to form the type and graphic elements that appear on it. Rather than download a font to the printer, the page description language gives the printer instructions for how to draw each character from outlines; graphics are produced in a similar way. Examples are Adobe PostScript and Xerox Interpress.

page header

Text that appears at the top of every page in a document, which may include page numbers, running heads, or other information.

page layout

The creation of a camera-ready page, including placement of text, pictures, and other design elements. Page layout can be done by hand, using cut and paste methods on a light table; on the computer using a page layout program; or a combination of both.

page layout program

A program used to create camera-ready copy. Examples are PageMaker, Corel Ventura Publisher, and QuarkXPress.

page makeup

The creation of a page for printing, including design elements such as type, images, headers, and footers.

page mode memory

A way of organizing memory access used commonly in DRAM chips. Ordinarily, each bit in memory is found by its row and column coordinates. Using page mode, a memory location can be found faster, because each row, or page, only needs to be selected once for all columns in that row.

page printer

A printer that prints a full page at a time; for example, a laser printer.

page recognition

The ability of software to recognize different kinds of items on a scanned page. Page recognition software can distinguish text from pictures, and converts text on the page into computer characters by means of optical character recognition (OCR).

page view

One user request to view a page. The number of times users request a page is used, for example, to determine how many times an ad is seen.

page zero

Memory locations 0 to 4095 in virtual memory.

PageMaker

A desktop publishing program from Adobe Systems, Inc., Mountain View, California. It was originally introduced by Aldus Corporation in a Macintosh version; it is now also available for PC.

pager

A small radio receiver which beeps to alert the wearer of messages or telephone calls. It displays the telephone number of the caller so the wearer can call back. Some pagers can display very short messages. Also called a beeper.

pagination

The numbering of pages. Many programs can be set up to automatically number pages when a file is printed.

paging

1. In a virtual memory computer, the transfer of pages between real storage and auxiliary storage. A page, in virtual memory, is a block of memory with its own virtual address. Paging increases the memory available to a program by temporarily transferring less-needed parts of the program's working memory from RAM into secondary storage. When a page is needed, it is read back into RAM, replacing another page which is moved into secondary storage. This juggling of memory is accomplished by a memory management unit (MMU). By using virtual memory this way, a computer can run tasks that exceed the limits of its physical memory. 2. A way of contacting a person whose exact location is not known, by means of messages, loudspeakers, and more recently by using compact electronic beepers or pagers.

pain in the net

A very annoying flamer.

paint program

A program that allows a user to “paint” on the computer screen. Using a mouse or other pointer, the user can select from various drawing and painting tools such as brushes, spray cans, etc. and a full palette of colors. The paint program uses bitmap graphics, and allow the user to control the color of each pixel. Sophisticated graphics editing capabilities such as screens, filters, etc., can be used. Painted images, which use raster graphics, are harder to scale and move around than vector graphics images. Examples of paint programs are Paint, Superpaint, Paintbrush, and Painter.

Paintbrush

A paint program for Microsoft Windows.

Painter

A paint program for Macintosh and Windows from Fractal Design Corporation, Aptos, California.

PAL

1. Phase Alternate Line (or Phase Alternation Line). The standard for color television broadcast throughout much of Europe, which has good color transmission and sends an analog signal at 625 lines of resolution 25 interlaced frames a second. France uses SECAM, and the United States uses NTSC. 2. Paradox Application Language. The programming language used with Paradox, a relational database program.

Palace, The

A multiplatform avatar-based graphical chat program.

palette

The color palette is the range of colors available to use within a program such as a paint or draw program, photo editing program, or page layout program. The tool palette is the collection of tools available to use, such as a paintbrush, charcoal, pencil, paint bucket, airbrush, etc.

PalmOS

An operating system specifically engineered for handheld devices and the small amount of memory they have available.

palmtop

A computer small enough to be carried in the palm of the hand.

pan

Short for panorama. To move one's view continuously across an area, or to move an area continuously across one's view. Passing a picture a little at a time in front of one's eyes, moving a movie or television camera across a scene, and using a computer screen to progressively display different parts of an image are all examples of panning. Panning is a mostly horizontal movement.

panic

The action taken by a program or an operating system when a serious problem makes it unable to run. It may include displaying an error message, freezing, or automatically rebooting.

PANS

Pretty Amazing New Stuff. See POTS.

Pansophic

A U.S. company specializing in software engineering.

Pantone Matching System

(PMS). A set of standard colors, with each color designated by a number. Printers use PMS sample books to pick colors and then mix the inks to the exact specifications. On the computer, many graphics programs allow the user to pick colors by PMS number and display the chosen colors (at least approximately) on the screen.

PAP

Password Authentication Protocol. A means of authenticating passwords which is defined in RFC 1334. PAP uses a two-way handshaking procedure. The validity of the password is checked at login. See also CHAP.

paper feed control character

(PFCC). A way of controlling paper feed to a line printer.

paper tape

1. A storage medium used in the early 1900s, also called punch tape. Data was stored by means of patterns of holes punched in the tape. 2. The rolls of tape used in cash registers and calculating machines.

paper-net or papernet

Regular postal service or snail mail.

paperless office

The idea of an office in which paper documents are no longer necessary. Many documents can now be stored and transferred by means of computer disks and networks, eliminating the need for hard copy. However, there are still many uses for paper.

Paradox

A relational database from Borland for IBM PC, Windows 95, and Windows NT. The Windows version has client/server capabilities.

paradox

An apparently sound argument, based on valid premises, that leads to a self-contradictory conclusion.

Paradox Application Language

(PAL). The programming language used with Paradox, a relational database program.

paragraph

From a grammatical point of view, a paragraph is one or more sentences grouped together and addressing a common subject. Word processing and hypertext markup languages treat as a paragraph any section of text that has paragraph formatting. Paragraph formatting is created by a character such as a line return at the end of the paragraph, or sometimes a character at the beginning of the paragraph.

parallel

Side by side. For example, a parallel interface can transmit eight bits (a whole byte) at one time, over eight parallel lines. A serial interface transmits only one bit at a time.

parallel computer

A computer that has more than one central processing unit; parallel computers are used for running multiple processes simultaneously.

parallel computing

Using more than one computer at the same time to solve a problem, or using a computer that has more than one processor working simultaneously (a parallel computer).

parallel interface

A port that transmits a number of bits at a time by means of multiple parallel channels. A parallel interface is used to connect the printer on a PC. A parallel interface may transmit eight bits (one byte) at a time, or several bytes at a time. A common parallel interface used in personal computers has 36 channels; eight channels are used to transfer a byte of data at one time, and the other channels are for addressing, error correction, and other control signals. A parallel interface is faster than a serial interface, but is not reliable to transmit data over long distances. Tape drives, ISA, and IDE use parallel interfaces.

parallel port

A socket on a computer for transmitting data in parallel, which means more than one bit at a time. There may be eight, 16, or 36 channels; each channel carries one bit of information, so eight channels would be used to transmit one eight-bit byte at a time. Not all the channels are used for data; some are used for control signals. A parallel port, also called a female connector, has 25 holes, and the cable that plugs into it has 25 pins. It is the kind of port used to connect tape drives, CD-ROMs, extra hard disks, and most printers. A parallel port transmits faster than a serial port, but cannot reliably send data more than 20 feet.

parallel processing

Using more than one computer at the same time to solve a problem, or using more than one processor working simultaneously within the same computer.

parallel processor

A computer that has more than one central processing unit, and can be used for parallel processing. Also called a parallel computer.

parallel transmission

The transmission of more than one bit at a time over parallel channels, as opposed to serial transmission in which one bit at a time is transmitted. A parallel cable can use eight channels to transmit one eight-bit byte at a time, or may transmit more than one byte at a time. Some of the channels may be used to transmit control signals instead of data.

param

Parameter.

parameter

In computing, a value sent to a program or operation by the user.

Parameter RAM

(PRAM). A kind of random access memory that holds basic settings for the Macintosh such as control panels and the desktop. It is refreshed by a battery when the computer is off. The PRAM can be cleared by holding down the option and command keys while booting the computer.

parameter-driven program

A program that requires the user to enter certain values (parameters) with which it then performs its operations.

paranoid security policy

A security policy which allows no access from the Internet to an organization's internal network.

PARC

Xerox Corporation's Palo Alto Research Center. The research center from which came many important innovations in the computer field, such as some elements of the graphical user interface (the mouse, windows, and icons), laser printers, object-oriented langauges, bitmap graphics, local area networks, and the personal computer itself. Most of these innovations, though discovered at PARC, were not marketed until other companies became interested in them.

parent file

In a database, the main file containing basic information about an item. One or more child files can be created with more detailed information.

parent program

The main program which is loaded into memory first, and then may load other programs (child programs).

parentheses

ASCII characters 40 and 41: ( ) , used to enclose and set off characters for various purposes in grammar, mathematics, and computer programming.

parenthesis-free notation

The same as Polish notation. A way of expressing a sequence of calculations without using parentheses to show which operation must be performed first. See Polish notation.

parity

An integer's property of being odd or even. Parity checking is used to detect errors in binary-coded data.

parity bit

When binary data (1s and 0s) is being transmitted or stored, an extra bit can be added to make the total number of 1s always odd (or always even). This extra bit is called a parity bit. If one bit of the data is transmitted incorrectly, the parity will change, making it possible to detect the error.

parity checking

An error detection technique in which an extra bit, called a parity bit, is added to each byte in a transmission, holding a 0 or 1 depending on whether the byte has an odd or even number of 1 bits. The sender and receiver agree on odd parity, even parity, or no parity. If they agree on even parity, a parity bit will be added that will make each byte even. If they agree on odd parity, a parity bit will be added that will make each byte odd. If the data is transmitted incorrectly, the change in parity will reveal the error.

parity error

A message which is displayed on the computer if an error in parity has been detected.

parse

1. To grammatically analyze a sentence or group of words, defining the parts of speech and their syntactic relationships. 2. To analyze a statement in a human or artificial language so it can be used by the computer. Parsing is used to convert natural language statements into high-level programming language, and to convert high-level programming languages into machine language.

parser

A software routine that analyzes a statement in a natural or artificial language and resolves it into a form that can be understood by the computer.

parser generator

A program which, given a formal description of a language, can generate a parser for it. An example is UNIX yacc.

partially qualified name

A qualified name that is not complete, containing some, but not all of the names in the hierarchical structure leading to the named item.

partition

A division of a disk or storage area.

Pascal

(Pa). A programming language designed by Niklaus Wirth in the early 1970s, as a simplification and modernization of ALGOL. It is named after Blaise Pascal, a French mathematician. Pascal, known for its simplicity and highly structured programming, was designed for teaching programming. Its restrictive nature makes it a safe tool for students, but can be a handicap in general-purpose programming. Nevertheless, Pascal became a widely used programming language, and was the basis for many later languages including Modula-2, Ada, dBASE, and PAL.

Pascal, Blaise

A French philosopher and mathematician (1623-1662) who developed a calculating machine in 1642.

Pascaline

Blaise Pascal's calculating machine, developed in 1642.

passive hub

A central device to which other devices connect, and which forwards signals. A passive hub can be used to connect several computers together in a star configuration; it does not regenerate signals or process them in any way.

passive matrix display

A type of liquid crystal display (LCD) which is sometimes used in portable computers. Instead of a transistor for each pixel as in active matrix display, a passive matrix display uses a series of criss-crossed wires having an LCD element at each place the wires intersect. A passive matrix display depends on its display elements to stay bright until the next refresh scan; it is not as bright as an active matrix display, but uses less power and is less expensive.

password

A secret sequence of letters and other symbols needed to log in to a
computer system as an authorized user. When a user enters a password, it appears as a line of asterisks ******* so no one can read it.

Password Authentication Protocol

(PAP). A means of authenticating passwords which is defined in RFC 1334. PAP uses a two-way handshaking procedure. The validity of the password is checked at login. See also CHAP.

password cracking

Using computer technology to discover someone else’s password, with the intent of unauthorized use.

password fishing

Attempting to con a user into revealing his or her password.

password protection

A technology that allows a system to assign login names and passwords to users. Files and directories are protected from unauthorized access by requiring users to enter a password before access is allowed.

password sniffer

A Trojan Horse program that downloads while an unsuspecting user is visiting a website, which detects the user’s password and sends it to the originator of the site.

password stealer

(PWS). A program embedded in a file to steal passwords. The user becomes vulnerable upon downloading the file. The next time the user logs on, the user's password is sent to the maker of the program, without the user's knowledge.

paste

An editing function which involves transferring text, images, or both from the clipboard into a desired location. The expression is taken from “cut and paste,” which is the way it was originally done, manually, on a layout table.

pastie

A small sticker that can be put on a keyboard key to show a special character that the key represents other than its normal character.

patch

A quick modification of a program, which is sometimes a temporary fix until the problem can be solved more thoroughly.

path

1. The exact directions to a file on a computer. These directions are usually described by means of the hierarchical filing system from the top down, stating the drive, directory, any subdirectories, the file itself, and its filename extension if it has one: c:jobscompany
esume.txt. This complete set of information is a fully qualified path. 2. The route between any two points, such as the communications channel between two computers.

pathname

The identification of a file by its name and the name of all directories leading to it. Example: zoo/animals/lions. Also called directory path.

pathname separator

A character used between the elements in a pathname. In UNIX, the / (forward slash) is used; DOS uses (backslash). Example: www. xcom.com/index/file.html

pattern recognition

A branch of artificial intelligence concerned with the identification of visual or audio patterns by computers. For the computer to recognize the patterns, the patterns must be converted into digital signals and compared with patterns already stored in memory. Some uses of this technology are in character recognition, voice recognition, handwriting recognition, and robotics.

pattern-matching character

A character that can be used to represent one or more other characters. In DOS and UNIX, ? can be used to represent any single character, and * can represent any group of characters. Therefore, “*.*” could be substituted for any file name; “*.BAK” would mean any .BAK (backup) file, etc.

PAX

Private Automatic Exchange. A private automatic telephone exchange that allows calls only within the exchange and not calls to or from the public telephone network.

payware

Software that is sold; commercial software (not freeware or shareware).

PB Cache

Pipeline Burst Cache or Pipelined Burst Cache. A type of cache using static RAM and pipeline processing. Pipeline burst cache is often used as a secondary cache in computers with high-speed processors to improve the computer's performance.

PBEM

Play By Electronic Mail. A kind of game playing in which each player's moves are sent to the other player(s) via electronic mail.

PBEM game

Play By Electronic Mail game. A kind of game, popular on Internet and BBS, in which each player's moves are sent to the other player(s) via electronic mail.

PBM

Play By Mail. A way of playing games in which each player sends moves by postal mail to the other player(s). It's now even faster to play by electronic mail (PBEM).

PBX

Private Branch Exchange. A telephone exchange used within an organization and located on the premises; an example would be the main switchboard in a hospital.

PC

Short for Personal Computer. There are many kinds of personal computers; PC usually refers to personal computers that conform to the standard of the IBM PC. There are more IBM PCs and PC clones in use worldwide than any other type of computer. The IBM PCs and PC clones are based on the Intel microprocessors and mostly are run with DOS or Windows. Some IBM PC models are the XT, AT, and the PS/2 numbered series which includes Models 25, 30, 50, 55, 60, 70, 80, and so forth. Some makers of PC clones are Compaq, HP, and Dell.

PC Bench

Ziff-Davis' standard benchmark for measuring the performance of PCs running DOS.

PC Card

(Personal Computer Card). Trademark name for a lightweight, removable module about the size of a credit card that adds features to a portable computer, developed by the Personal Computer Memory Card International Association (PCMCIA). It is also called the PCMCIA card. A PC Card may add memory, modem and networking capability, a radio transceiver, more hard drive space, or enhanced sound. It is a plug and play device which uses a 16-bit socket and a 68-pin connector. All PC Cards are the same length and width, but varying thicknesses are used for laptops, palmtops, etc., and according to amount of storage space required.

PC card

An expansion card for a PC. A printed circuit board which can be plugged into the computer's expansion slot to add a new feature; for example, a modem, a higher-quality display, or sound.

PC compatible

A personal computer which is compatible with the IBM PC.

PC EXPO

A trade show held twice a year (in New York in the summer, in Chicago in the fall), sponsored by the Blenheim Group PLC.

PC Paintbrush

A PC paint program from ZSoft Corporation, Marietta, Georgia.

PC-DOS

Personal Computer-Disk Operating System. An operating system developed by Microsoft and supplied with IBM PCs. Microsoft also developed MS-DOS, a very similar operating system, to be used with non-IBM PCs. Starting with DOS 6, MS-DOS and PC-DOS have different sets of auxiliary utility programs. MS-DOS and PC-DOS are both called DOS for short.

PCI

Peripheral Component Interconnect. A personal computer local bus designed by Intel, which runs at 33 MHz and supports Plug and Play. It provides a high-speed connection with peripherals and allows connection of seven peripheral devices. It is mostly used with Pentium computers but is processor independent and therefore able to work with other processors. It plugs into a PCI slot on the motherboard and can be used along with an ISA or EISA bus.

PCI bus

Peripheral Component Interconnect bus. A personal computer local bus designed by Intel, which runs at 33 MHz and supports Plug and Play. It provides a high-speed connection with peripherals and allows connection of seven peripheral devices. It is mostly used with Pentium computers but is processor independent and therefore able to work with other processors. It plugs into a PCI slot on the motherboard and can be used along with an ISA or EISA bus.

PCI slot

Peripheral Component Interconnect slot. A slot on the motherboard which is available to plug in a PCI bus.

PCI slots

Peripheral Component Interconnect slots. A PCI slot is a socket on the motherboard of the computer where a PCI bus can be plugged in.

PCjr

(PC junior). The first home computer from IBM, introduced in 1983.

PCL

Printer Control Language. The control language for HP LaserJet printers, also supported by many other printers and typesetting machines. PCL tells the printer how to print a page, as does a page description language.

PCM

A generic term for the decoding technology used in the creation of WAV files.

PCMCIA

(Personal Computer Memory Card International Association; also People Can't Memorize Computer Industry Acronyms). A Sunnyvale, California nonprofit trade association created to standardize the connection of peripherals to portable computers. PCMCIA developed the PC Card (often called the PCMCIA card), a lightweight, removable module about the size of a credit card that adds features to a portable computer.

PCMCIA card

(Personal Computer Memory Card International Association card). A lightweight, removable module about the size of a credit card that adds features to a portable computer. Its official name is the PC Card. A PCMCIA card may add memory, modem and networking capability, a radio transceiver, more hard drive space, or enhanced sound. It is a plug and play device which uses a 16-bit socket and a 68-pin connector. All PCMCIA cards are the same length and width, but varying thicknesses are used for laptops, palmtops, etc., and according to amount of storage space required.

PCS

(Personal Communication Services). Wireless communications services that use the 1900 MHz (1.9 GHz) band rather than the 800 MHz used for cellular, and that use digital technology for transmission and reception.

PCUG

PC User Group.

PD

Public Domain. Belonging to the public; not protected by copyright.

PDA

Personal Digital Assistant. A pocket-sized personal computer. PDAs usually can store phone numbers, appointments, and to-do lists. Some PDAs have a small keyboard, others have only a special pen that is used for input and output. A PDA can also have a wireless fax modem. Files can be created on a PDA which are later entered into a larger computer. Apple's Newton is a well-known PDA.

PDC

Personal Digital Communications. A second-generation wireless service which uses a packet-switching technology. Messages are split into packets of data for transmission, then reassembled at their destination. PDC is widely used in Japan.

PDF

See .PDF.

pdksh

A free UNIX Korn shell.

PDL

Page Description Language. A language that describes to the printer how to print a page and how to form the type and graphic elements that appear on it. Rather than download a font to the printer, the page description language gives the printer instructions for how to draw each character from outlines; graphics are produced in a similar way. Examples are Adobe PostScript and Xerox Interpress.

PeaceNet

A network sponsored by the Institute for Global Communications for the purpose of improving worldwide communication and international relations. The network makes it possible for people involved in peace initiatives around the world to communicate with each other and share news about relevant events.

peer-to-peer network

A communications network in which any computer on the network can be a client and/or a server. Any computer can access files on any other computer in the network. Two examples are Artisoft's LANtastic and Microsoft's Windows for Workgroups.

Pegasus

An emailer program that has filtering and mailing list capabilities, available as freeware for PC and Macintosh.

PEM

Privacy Enhanced Mail. Electronic mail with confidentiality, authentication, and message integrity.

pen interface

A way of inputting information into a computer by writing with a special pen on a computer screen.

pen-based interface

A user interface in which the computer operator chooses commands and communicates with the computer by means of an inkless pen called a stylus, writing on an LCD panel or electronic tablet.

Pentium

An Intel high-performance microprocessor introduced in 1993, also called P5, 586, or 80586. The name Pentium refers to the fact that it is the fifth microprocessor in the 80×86 series. It is about twice as fast as the 486.

Pentium II

An Intel microprocessor that is an improvement on the design of the Pentium Pro, with 2 million transistors added to bring the total up to 7.5 million, and speeds of 233, 266, 300, and 333 MHz. In addition, the Pentium II features Dual Independent Bus (DIB) architecture; a singled edge contact (SEC) cartridge that fits into Slot 1; a 32K L1 cache; a 512K L2 cache; and support for MMX.

Pentium III

The Intel microprocessor that follows the Pentium II. The Pentium III runs at 450, 500, 533, 550, or 600 MHz and offers new multimedia capabilities, including full-screen, full-motion video and realistic graphics, and improvements in high-performance business desktop computing. Other features include 70 new instructions; P6 architecture; 133- or 100-MHz system bus; and a 512K L2 cache.

Pentium Pro

Successor to the Pentium microprocessor; also called P6, 686, or 80686. The P6 has internal RISC architecture and a CISC-RISC translator. It is faster than the Pentium for 32-bit software but slower for 16-bit software.

PeopleLink

An instant messaging program from idealab!

per seat

A way of licensing software based on the number of workstations on which it will be installed and used.

percent sign

ASCII character 37: % .

peripheral

Any piece of hardware connected to a computer; any part of the computer outside the CPU and working memory. Some examples of peripherals are keyboards, mice, monitors, printers, scanners, disk and tape drives, microphones, speakers, joysticks, plotters, and cameras.

Peripheral Component Interconnect

(PCI). A personal computer local bus designed by Intel, which runs at 33 MHz and supports Plug and Play. It provides a high-speed connection with peripherals and allows connection of seven peripheral devices. It is mostly used with Pentium computers but is processor independent and therefore able to work with other processors. It plugs into a PCI slot on the motherboard and can be used along with an ISA or EISA bus.

peripheral device

Any piece of hardware connected to a computer; any part of the computer outside the CPU and working memory. Some examples of peripheral devices are keyboards, mice, monitors, printers, scanners, disk and tape drives, microphones, speakers, joysticks, plotters, and cameras.

peripheral devices

Hardware connected to a computer; any part of the computer outside the CPU and working memory. Some examples of peripheral devices are keyboards, mice, monitors, printers, scanners, disk and tape drives, microphones, speakers, joysticks, plotters, and cameras.

peripherals

The hardware connected to a computer; the parts of the computer outside the CPU and working memory. Some examples of peripherals are keyboards, mice, monitors, printers, scanners, disk and tape drives, microphones, speakers, joysticks, plotters, and cameras.

Perl

Perl is a
general-purpose
programming language
invented in 1987 by Larry
Wall. With over one
million users worldwide, it
has become the language
of choice for World Wide
Web development, text
processing, Internet
services, mail filtering,
graphical programming,
systems administration,
and every other task
requiring portable and
easily-developed
solutions.

permanent font

1. A resident font. 2. A downloadable font that stays in the printer’s memory until the printer is turned off.

permanent virtual circuit

(PVC). A point-to-point connection that is established in advance. A PVC which is defined at the time of subscribing to a service is called a VPN (virtual private network). Contrast with switched virtual circuit.

permissive security policy

A security policy which allows access from the Internet to an organization's internal network, except for traffic which is specifically prohibited. Access is controlled by packet filtering gateways.

persistence

The quality or state of continuing for a long time. In computing, persistence can refer to the length of time a phosphor dot on a display screen remains illuminated after being energized by an electron beam. Persistence also refers to the quality of objects and data which remain in memory from session to session.

persistent

Existing for a long time or continuously; having persistence.

Personal Communication Services

(PCS). Wireless communications services that use the 1900 MHz (1.9 GHz) band rather than the 800 MHz used for cellular, and that use digital technology for transmission and reception.

Personal Computer

See PC. for a definition of personal computer.

Personal Computer Memory Card Internatio

(PCMCIA). A Sunnyvale, California nonprofit trade association created to standardize the connection of peripherals to portable computers. PCMCIA developed the PC Card (often called the PCMCIA card), a lightweight, removable module about the size of a credit card that adds features to a portable computer.

personal digital assistant

(PDA). A pocket-sized personal computer. PDAs usually can store phone numbers, appointments, and to-do lists. Some PDAs have a small keyboard, others have only a special pen that is used for input and output. A PDA can also have a wireless fax modem. Files can be created on a PDA which are later entered into a larger computer. Apple's Newton is a well-known PDA.

Persuasion

A program from Aldus which is used to create presentation graphics.

peta-

Quadrillion; 10^15. Or, in binary, 2^50 = 1,125,899,906,842,624.

petabyte

A quadrillion bytes (10^15 bytes or 2^50 bytes).

PFCC

Paper Feed Control Character. A way of controlling paper feed to a line printer.

PgDn

Page Down. This keyboard key is used to view the page below the current page showing in a screen or window.

PGM

Pragmatic General Multicast. One of two common transport protocols for general multicasting.

PGML

Precision Graphics Markup Language. A two-dimensional, scalable graphics language for increasing the ease and precision with which graphic images can be produced and integrated into documents. PGML is an application of XML, and PGML graphics can be modified with style sheets along with the XML documents that contain them.

PGP

Pretty Good Privacy. An encryption program based on RSA (Rivest-Shamir-Adleman) public-key cryptography. PGP allows users to exchange files and messages, with both privacy and authentication, over all kinds of networks. The messages are unreadable unless the receiver has an encryption key. PGP encrypts data using the IDEA (International Data Encryption Algorithm) with a randomly generated key, then encrypts the key using the receiver's public key. After the message is transmitted, PGP uses the receiver's private RSA key to decrypt the IDEA key, then decrypts the message using that key. PGP features keys longer than 128 bits, and can be used with UNIX, DOS, Windows, and Mac. Because PGP is based on public-key cryptography, no secure channels are needed to exchange keys between users. PGP can also provide digital signatures for files or messages. Free versions of PGP can be downloaded from various BBS and Internet sources. Commercial versions are available from Viacrypt.

PGPfone

A technology that uses a computer with a sound card/microphone, a modem, and PGP to encrypt telephone conversations. The voice messages are digitized, encrypted using PGP, transmitted, then decrypted and played by means of the sound card.

PgUp

Page Up. This keyboard key is used to view the page above the current page showing in a screen or window.

PH

A tool for finding people online. The Macintosh Eudora equivalent of UNIX Finger.

phase alternate line

(PAL). The standard for color television broadcast throughout much of Europe, which sends an analog signal at 625 lines of resolution 25 interlaced frames a second, giving accurate color transmission. France uses SECAM, and the U.S. uses NTSC.

PHIGS

Programmers Hierarchical Interactive Graphics System. An ANSI and ISO standard for a device-independent application programming interface used with two- and three-dimensional graphics applications in high-performance workstations.

phone tag

Two senders trying to reach other by telephone but always reaching each other's voice mail and leaving messages instead.

Photo CD

An imaging system from Kodak for storing 35mm slides or negatives on a CD-ROM. It can store 100 photographs. A drive that conforms to the CD-ROM XA standard is needed to read the files. A Kodak Photo CD player can be used to view Photo CDs on a TV screen. The Power CD from Apple also includes this capability (see Power CD).

Photo CD Catalog

A Photo CD format which can hold thousands of pictures.

Photo CD Medical

A Photo CD that can store film-based images.

Photo CD player

A CD player from Kodak that can show Photo CDs on a TV screen, and can also play audio CDs.

Photo CD Portfolio

A Photo CD format which holds up to 800 television-quality images.

photonic integrated circuit

Photonic integrated circuits are a technology in development. The proposed chips would use light rather than electrical current, generate little or no heat, make faster switching possible, and be immune to electrical noise.

Photoshop

An image editing program from Adobe Systems, Inc., Mountain View, California, available for Macintosh and Windows.

Photostyler

A graphics program for Windows.

phototypesetter

A machine that produces high-quality typeset copy for printing. The type is input by means of a keyboard and output on photographic paper or film. Phototypesetters preceded desktop publishing and laser printers. A further evolution is the imagesetter, which can produce high-quality graphics as well as type.

phreaking

Hacking into telecommunications systems, often in order to make free telephone calls.

phtml

(Pre-HTML). Some HTML documents have embedded equations or other material not expressible in HTML. To embed the non-HTML data, preprocessing instructions (PPIs) are used. Using a program called phtml, the document is then translated into a new HTML document with the equations included as inline pictures. These HTML documents with PPIs have the file extension .PHTML.

physical layer

Layer 1 of the Open Systems Interconnection (OSI) networking model, which concerns the mechanical, electrical and functional aspects of connections in a communications medium.

physical memory

See RAM.

PIC microcontrollers

PIC microcontrollers were designed by Microchip and have been around for over 20 years. They were the first RISC (Reduced Instruction Set Computers) microcontrollers. For their small size and low power consumption, PIC micrcontrollers are gaining in popular among desingers and hobbyists. They are the found inside BASIC Stamp computers.

pica

1. A typewriter type that prints 10 characters per inch. Fixed-pitch computer printers usually print 10 cpi. 2. In typesetting, a pica is a measurement of space which is the same as 12 points, originally a little less than 1/6 inch. In computer page layout, pica measurement is usually represented as exactly 6 picas per inch.

picklist

A dialog box that has a scrollable list of choices from which the user can pick.

pico-

(Pronounced pee-ko.) The SI prefix meaning one trillionth or 10^-12.

picoJava

An inexpensive RISC processor which executes Java instructions without the need for an interpreter or compiler. Because picoJava executes the Java Virtual Machine instructions directly, Java applications designed for use with picoJava can be 1/3 as large but run many times faster than with a standard processor. The greatly reduced memory requirements make this chip good for hand-held PCs, cellular telephones, pagers, and network computers.

picosecond

One trillionth of a second; one thousandth of a nanosecond.

PicTeX

A version of TeX used for pictures.

Picture Level Benchmark

(PLB). A benchmark for measuring graphics performance.

picture quality scale

(PQS). A way of measuring the quality of an image by how well it is perceived by the human eye, instead of measuring differences in pixels as perceived by the computer.

pidgen+

A language used with the Apple II.

piggyback board

A small circuit board that plugs into a larger circuit board to add to its capabilities.

PING

Packet Internet Groper. A program used to test whether a particular network destination is online, by sending an Internet control message protocol (ICMP) echo request and waiting for a response. (Also called packet internet gopher).

PIO

Programmed Input/Output. Data transfer between two devices in which the data path goes through the computer's main processor. The speed of data transfer corresponds with the PIO mode: PIO mode 0 has a speed of 3.3 MBps; mode 1 is 5.2 MBps; mode 2 is 8.3 MBps; mode 3 is 11.1 MBps; mode 4 is 16.6 MBps.

pipe

1. The method by which you are connected to the internet. A “fat pipe” is a line with T1 or higher capacity. 28.8 modem users may complain: “I need a bigger pipe.” 2. A designated amount of memory used by one process to pass information along to another; that is to say, a “pipe” connects two processes so one's output can be used as the other's input.

pipeline burst cache or pipelined burst

(PB Cache). A type of cache using static RAM and pipeline processing. Pipeline burst cache is often used as a secondary cache in computers with high-speed processors to improve the computer's performance.

pipeline processing

A method of processing in which a task is performed in stages; the output of one stage is input to the next. This speeds up processing by allowing several parts of different tasks to be run at the same time.

pitch

The number of characters per inch in a given typeface. In fixed-pitch type, every character has the same width; in proportional-pitch type, some characters are wider than others, and the pitch is measured as an average character width.

pixel

Short for picture element. A pixel is the smallest logical unit of visual information that can be used to build an image. Pixels are the little squares that can be seen when a graphics image is enlarged. The more pixels in an image, the better its resolution.

pixel depth

In bitmap graphics, the number of bits per pixel, which determines the number of shades of gray or variations of color that can be displayed by a computer monitor. For example, a monitor with a pixel depth of 16 bits can display 65,536 different colors; a monitor with a pixel depth of 24 bits can display 16,777,216 colors. See 4-bit color, 8-bit color, 15-bit color, 16-bit color, 24-bit color, 32-bit color.

pixel graphics

Graphic images composed of an arrangement of little squares called pixels. Also called bitmapped graphics or raster graphics.

pixel map

A 3-dimensional array of bits represented as a 2-dimensional array of pixels, in which each pixel has a depth of a certain number of bits.

pixelated or pixellated

Visible as a pattern of pixels. A bitmapped image can be made of tiny squares which are not individually distinguished by the eye. When the image is enlarged, the pattern of squares is more obvious.

pixelation or pixellation

An effect which occurs when a bitmapped image is enlarged so that the individual pixels are obvious to the eye.

pixels

A pixel is the smallest logical unit of visual information that can be used to build an image. Pixels are the little squares that can be seen when a graphics image is enlarged. (The word pixel is short for picture element.) The more pixels in an image, the better its resolution.

pixmap

A 3-dimensional array of bits represented as a 2-dimensional array of pixels, in which each pixel has a depth of a certain number of bits.

PKI

Public Key Infrastructure

PKLite

A program from PKWare that compresses only .EXE and .COM files. PKLite files decompress automatically when loaded.

PKSFX

A file compression utility from PKWare that compresses a file into a self-extracting .EXE file.

PKUNZIP

A decompression program from PKWare for the PKZIP compression utility. It was originally for PCs, but there are versions for other computers.

PKWare, Inc.

A company in Brown Deer, Wisconsin that makes the PKZIP and PKUNZIP compression utilities. PK stands for Phil Katz.

PKZIP

A file compression utility from PKWare, available as shareware. The decompression utility is PKUNZIP. PKZIP was originally for MS-DOS, but third-party versions are available for other platforms.

place

To import a file into another file.

plain old telephone service

(POTS). The standard analog telephone service with no enhancements like call waiting, etc. POTS is said to be evolving into PANS (Pretty Amazing New Stuff).

plaintext

Text which is decrypted or nonencrypted, as opposed to ciphertext. 2. A file stored as plain ASCII data.

Platform

Computers are layered machines composed of (1) a chip-level hardware level, (2) an operating system level, and (3) an application-programs level. The platform layer of the computer is the bottommost level of these levels. In layman's terms, the platform refers to the type of operating system (Windows, DOS, Unix) or computer (PIII) being used.

play by electronic mail

(PBEM). A kind of game playing in which each player's moves are sent to the other player(s) via electronic mail.

play by mail

(PBM). A way of playing games in which each player sends moves by postal mail to the other player(s). It's now even faster to play by electronic mail (PBEM).

PLB

Picture Level Benchmark. A benchmark for measuring graphics performance.

PLCC

Plastic Leadless Chip Carrier. A less expensive version of the leadless chip carrier, which is a square chip housing with flat contacts, instead of pin connectors, on each side.

PLMK

Please Let Me Know (chat).

plug

A connector that fits into a socket. See also male connector.

plug and play

(PnP). The ability of a computer to automatically detect and configure new hardware components when they are plugged in, without requiring the user to go through complicated installation procedures. With plug and play, it should be possible to immediately use a new peripheral as soon as it is plugged in. Macintosh equipment has always been plug and play; PC users have it since Windows 95. A computer must have a plug and play BIOS on the motherboard as well as the right operating system for plug and play. Expansion boards are designed specifically for plug and play, though if an older expansion board is added, the plug and play system will help the user find the correct settings for it.

plug and pray

What you do when you're hoping plug and play will work.

plug-in

An accessory program that enhances a main application. An example is the set of additional tools and effects available to Photoshop image editor in the Plug-ins folder. There are many plug-ins for Netscape Navigator such as Shockwave and Crescendo MIDI player that give the browser special capabilities, especially for multimedia Web sites.

plug-ins

Accessory programs that enhance a main application. See plug-in.

Pluggable Authentication Modules

Primarily used by Linux servers, PAM serves as a program that simplifies and supports authentication services. When PAM is used, system administrators do not have to recompile programs when changing user authentication schemes. Instead, a system administrator can modify authentication policies as needed by editing configuration files in PAM.

plus

ASCII character 43: + . Used as a mathematical symbol.

PLV

Production-Level Video. Very high-quality video compression, used in Digital Video Interactive technology.

PM

Preventive Maintenance. Regular inspection of computer hardware to prevent problems before they happen.

PMOS

Positive-channel Metal Oxide Semiconductor. A semiconductor technology that uses positively charged base material. PMOS circuits are used in CMOS design and in calculators and watches.

PMS

Pantone Matching System. A set of standard colors, with each color designated by a number. Printers use PMS sample books to pick colors and then mix the inks to the exact specifications. On the computer, many graphics programs allow the user to pick colors by PMS number and display the chosen colors (at least approximately) on the screen.

PNG

Acronym for Portable Network Graphics (pronounced ping), a file format for bitmapped graphic images approved by the World Wide Web Consortium as a replacement for GIF files. GIF files use a patented data compression algorithm; PNG is patent- and license-free.

PnP

Plug and Play. The ability of a computer to automatically detect and configure new hardware components when they are plugged in, without requiring the user to go through complicated installation procedures. With plug and play, it should be possible to immediately use a new peripheral as soon as it is plugged in. Macintosh equipment has always been plug and play; PC users have it since Windows 95. A computer must have a plug and play BIOS on the motherboard as well as the right operating system for plug and play. Expansion boards are designed specifically for plug and play, though if an older expansion board is added, the plug and play system will help the user find the correct settings for it.

PNP

A bipolar transistor which has a layer of N-doped material between two layers of P-doped material.

POC

Point of Contact. A contact person for a domain, IP network, or other Internet entity.

pocket computer

A computer that can fit in the user's pocket. Pocket computers run on batteries, and can be plugged into a larger computer to transfer data.

POE

PowerOpen Environment. A hardware-independent standard for open systems based on the PowerPC architecture. The standard includes API and ABI specifications. Applications certified under this standard are compliant with X/Open and Spec 1170, and will run on PowerPCs under any PowerOpen-compliant operating system. X Windows, Motif, DOS, Windows, and Macintosh applications can be run in a PowerOpen Environment.

point

1. A period or decimal point symbol. 2. A unit of measurement in typesetting; there are 72 points in an inch. Points are used to measure the height of text characters, the leading, and the vertical space between design elements. 3. To use the cursor to locate a spot on the computer screen.

point of contact

(POC). A contact person for a domain, IP network, or other Internet entity.

Point of Presence

(POP or PoP). The closest site where a user can connect to an Internet server or other remote server; or, the location where a line from a long-distance telephone carrier makes a local connection. Some Internet service providers have PoPs in several different locations so more customers can reach the service with a local call.

Point of Purchase

(POP). A terminal or vending machine in a store or shopping mall where a customer can view products with their prices and select items to buy.

point of sale

(POS). The time and place in which a transaction is made. Point of sale computer systems include cash registers, optical scanners, magnetic card readers, and special terminals. Reading product tags, updating inventory, and checking credit are some of the operations performed at the point of sale.

point size

A size used to measure typefaces. In a graphical user interface, point size can be set by selecting an area of type with the cursor and selecting a size from a pull-down menu. Newspaper column type is commonly 10 point. Book text type is usually 10, 11, or 12 point.

Point to Point Protocol or Point-to-Poin

(PPP). A protocol for communication between computers using TCP/IP, over standard telephone lines, ISDN, and other high-speed connections. PPP was developed by the Internet Engineering Task Force (IETF) and is defined in RFC 1171. It can be used to connect a computer to the Internet, for services such as the World Wide Web and email. PPP is faster than SLIP and has better error correction; it can be used with both synchronous and asynchronous transmission.

point-of-sale computing

(POS computing). Using computers to record sales data at the time and place in which a transaction is made. Point of sale computer systems include cash registers, optical scanners, magnetic card readers, and sometimes a main computer which communicates with terminals. Scanners are used to read the Universal Product Code (UPC) on the tag, which records the price and type of item sold.

point-of-sale device

A device for recording sales information at the time and place a transaction occurs. See point of sale (POS).

Point-to-Point Tunneling Protocol

(PPTP). A version of PPP (Point-to-Point Protocol) that has the ability to encapsulate packets of data formatted for one network protocol in packets used by another protocol. This tunneling technique allows TCP/IP data to be transmitted over a non-TCP/IP network. PPTP can be used to join different physical networks using the Internet as an intermediary.

pointer

1. A symbol displayed on the computer screen that is moved by means of a pointing device such as a mouse, stylus, trackball, etc. The symbol may look like an arrow or other object. The pointer can be used to locate a specific point or object on the screen, to select and move objects, to select items on a menu, etc. 2. In programming, an address or an instruction to jump to another part of the data structure. 3. A hypertext link on a WWW page.

pointing device

An input device that is used to move the pointer on the computer screen. Examples are the mouse, stylus, trackball, pointing stick and touchpad.

pointing stick

A pointing device used on some notebook computers which resembles a pencil eraser, found between G, B, and H on the keyboard. It is operated with one finger to move the cursor on the screen.

Poisson distribution

A method of determining the probability of occurrence of an unlikely event within a large number of independent trials. For example, if the average number of users at any time on a network is known, Poisson distribution can be used to determine the minimum or maximum number of users in a certain time period. Named after S.D. Poisson, French mathematician.

Poisson, Simeon Denis

A French mathematician (1781-1840). He developed the statistical method called Poisson distribution.

Polish notation

A way of expressing a sequence of calculations without using parentheses to show which operation must be performed first. For example, the expression 2(4+5), which instructs the reader to add 4 + 5 and multiply by 2, would be written * 2 + 4 5 in Polish notation. To make the calculation, read from right to left until you find an operation, then perform the operation on the numbers immediately to the right of it, and continue to the next operation. So * 2 + 4 5 becomes * 2 9 and then 18. Reverse Polish notation is worked from left to right. Polish notation was invented by Jan Lukasiewicz. Many calculators and programming language interpreters translate algebraic expressions into Polish notation before performing the calculations.

poll

1. To check the devices attached to a telecommunication line one after another, to see if any terminal is ready to transmit. 2. To check devices or memory locations for operational status or occurrence of an external event.

polling ID

Polling identification. The unique character(s) identifying a communications terminal, used for polling.

polling list

The list of stations to be polled, in sequence.

polyalphabetic cipher

A cipher in which several substitutions and/or transpositions are used.

polycarbonate plastic

The material out of which CDs and CD-ROMs are made.

polygon

In computer graphics, a sequence of straight lines that enclose an area and together form a multi-sided figure that can be filled or moved around as one object.

polygons per second

(PPS). A measurement of 3D graphics performance by drawing speed.

polyline

In computer graphics, a figure composed of a sequence of connected lines.

polymorphic

Having many forms.

polymorphic virus

A virus that changes its form with each file it infects. Since they have no consistent binary pattern, such viruses are hard to identify.

PolyView

A Windows utility for viewing GIF, TIFF and JPEG files.

poor fusing

A problem that sometimes affects printers and photocopy machines in which
the toner can be easily rubbed off the printed page. It can be caused by not enough heat in the fusing system.

pop

To take something off a stack.

PoP

Point of Presence. The closest site where a user can connect to an Internet server or other remote server; or, the location where a line from a long-distance telephone carrier makes a local connection.

POP

1. Post Office Protocol. A protocol used by mail clients to download messages from a mail server on the Internet. 2. Point of Presence. The closest site where a user can connect to an Internet server or other remote server; or, the location where a line from a long-distance telephone carrier makes a local connection. 3. Point of Purchase. A terminal or vending machine in a store or shopping mall where a customer can view products with their prices and select items to buy.

pop-up menu

A menu that expands when clicked on with a mouse or other pointer. A list of options appears, and the user can select one by scrolling through the menu with the mouse button held down, and releasing the mouse button at the desired option.

POP3 host

(Post Office Protocol, version 3 host). The central repository where electronic mail is stored before the recipient downloads it; analogous to a U.S. Mail post office box where mail is stored waiting to be picked up. In an email address, the POP3 host is the part to the right of the @ symbol.

POP3 or pop3

(Post Office Protocol, Version 3). A protocol, or set of rules, by which a client machine can retrieve mail from a mail server.

port

1. A socket at the back of a computer used to plug in external devices such as a modem, mouse, scanner, or printer. 2. In a communications network, a logical channel is identified by its unique port number. 3. To translate software from one computer system to another.

port expander

A device that enables a number of lines to be connected to one port in a computer, and may offer more than one type of interface.

port replicator

A device that is used to connect peripherals to a portable computer. It has all the same ports as those on the portable computer. The peripherals, such as a monitor, printer, modem, etc., are kept plugged into the port replicator; then the portable computer can be quickly plugged into the one unit, instead of having to connect each peripheral individually.

portability

Ease of transfer from one system to another; ease of use with a variety of platforms without modification. The term usually refers to software.

portable computer

Any computer small and light enough to carry, such as a laptop, notebook, pocket computer, or palmtop.

Portable Document Format

See .PDF.

Portable Operating System Interface for

(POSIX). A set of standards from IEEE and ISO that define how programs and operating systems interface with each other. POSIX-compliant operating systems include Windows NT and most versions of UNIX.

portable software

Software that can be used on more than one hardware platform, and easily switched from one to another.

portal

1. A gateway or entrance. 2. A gateway to the Internet, which may be a search engine or directory web page. Examples: Infoseek, Excite, Yahoo, Lycos, AOL. A web page which is a starting point for web surfing.

portals

Web pages that serve as gateways to the Internet. A user can set up a browser to open on a favorite portal page, which is a starting point for web surfing. Most portals have links to a variety of interesting sites, and some kind of search engine or Web directory. Examples of portals are Infoseek, Excite, Yahoo, Lycos, AOL.

Portico

A virtual assistant from General Magic; a hand-carried device that reads email, screens and forwards telephone calls, and handles voice mail; it is voice activated.

porting

Translating software from one platform to another.

portrait

A way of positioning a page so it is taller than it is wide, as in portrait painting; the most common way of orienting a letter-sized page for printing. A computer printer usually gives the user a choice between portrait orientation and its opposite, landscape.

ports

1. Sockets at the back of a computer where external devices such as a modem, mouse, scanner, or printer can be plugged in. 2. In a communications network, a port is a logical channel identified by its unique port number.

POS

Point Of Sale. The time and place in which a transaction is made. Point of sale computer systems include cash registers, optical scanners, magnetic card readers, and special terminals. Reading product tags, updating inventory, and checking credit are some of the operations performed at the point of sale.

positive-channel metal oxide semiconduct

(PMOS). A semiconductor technology that uses positively charged base material. PMOS circuits are used in CMOS design and in calculators and watches.

POSIX

Portable Operating System Interface for UNIX. A set of standards from IEEE and ISO that define how programs and operating systems interface with each other. POSIX-compliant operating systems include Windows NT and most versions of UNIX.

POST

Power On Self Test. A test the PC performs on its hardware, CPU, and memory when the power is switched on.

post

To send a message to a newsgroup or mailing list. Postings are read by all; messages for individuals on a mailing list or in a newsgroup can be sent by email.

Post Office Protocol

(POP or P.O.P.). A protocol used by mail clients to download messages from a mail server on the Internet.

Postal, Telegraph, and Telephone

(PTT). The government agency that oversees postal, telegraph, and telephone services in some European countries.

postcardware

Shareware for which the only payment asked is sending a postcard to the developer.

postfix notation

The same as reverse Polish notation. A way of expressing a sequence of calculations without using parentheses to show which operation must be performed first. For example, the expression 2(4+5), which instructs the reader to add 4 + 5 and multiply by 2, would be written 2 4 5 + * in postfix notation. To make the calculation, read from left to right until you find an operation, then perform the operation on the numbers immediately to the left of it, and continue to the next operation. So 2 4 5 + * becomes 2 9 * and then 18. See also Polish notation.

Postgres

An object-relational database that is superior to traditional databases, though at times compatibility with postgres is more difficult to achieve than that with traditional databases. Postgres incorporates the below, which are unique to it as an object-relational database: classes, inheritance, types, functions; and additional features include, constraints, triggers, rules, and transaction integrity.

posting

A message sent to a mailing list or newsgroup.

PostScript

A page description language from Adobe Systems, Inc. PostScript translates the text and graphic images that appear on the computer screen into instructions for the printer. PostScript must be used with a printer that can interpret it.

PostScript Level 2

An enhanced version of PostScript which has improvements in color halftone screening, color matching, and memory management, built-in image file decompression, and the ability to work with extended character sets.

PostScript printer

A printer capable of interpreting the PostScript page description language, used for high-quality graphics and type.

PostScript printer description file

(PPD file). A file that gives the PostScript driver information about a printer.

potentiometer

1. An instrument that measures voltage or potential difference by comparing it to a standard voltage. 2. A 3-terminal resistor used to control the amount of current flowing through a circuit. The volume control on a radio or television set is an example.

POTS

Plain Old Telephone Service. The standard analog telephone service with no enhancements like call waiting, etc. POTS is said to be evolving into PANS (Pretty Amazing New Stuff).

pound sign

ASCII character 35: # .

POV

Point Of View. A term used in virtual reality.

power adapter

A transformer plugged into a wall outlet that converts the AC power from the outlet into DC power for an electronic device such as a modem.

power cycle

To turn a machine's power off and then on again, in hopes of curing a problem such as a frozen or hung state.

power down

To turn off a computer following the normal procedure, closing any open applications programs before turning off the power. This is the safe way to shut down the computer, and avoids loss of data.

power hit

A sudden increase or decrease in electric power supply, which can cause the computer to crash. Surge protectors are used to avoid problems from such variations in power.

Power Macintosh

(PowerMac). A personal computer from Apple which runs the Macintosh System 7.5 operating system and can also run DOS and Windows applications.

power management

Conserving battery power by switching to a low power consumption mode when not in use. Many portable computers, certain CPUs, and some other components have this feature.

Power PC

See PowerPC.

power save mode

A mode in which a computer uses very little power. Many portable computer components switch to power save mode when not in use, to conserve battery life.

power surge

A sudden rise of current or voltage in an electrical circuit that can last up to several seconds. A power surge can cause damage to a computer or its files if there is no surge protector.

power up

To turn a computer on following the normal procedure.

PowerBook

A popular series of Macintosh portable computers from Apple.

PowerCD

A CD-ROM player from Apple that can be connected to a television for use with photo CDs, a stereo for use with audio CDs, or to a Macintosh computer for both photo and audio CDs, plus data CDs.

PowerMac

(Power Macintosh). A personal computer from Apple which runs the Macintosh System 7.5 operating system and can also run DOS and Windows applications.

PowerOpen Association

An organization in Cupertino, California, which defines, sets standards for, and promotes the PowerOpen Environment, a hardware-independent standard for open systems based on the PowerPC architecture.

PowerOpen Environment

(POE). A hardware-independent standard for open systems based on the PowerPC architecture. The standard includes API and ABI specifications. Applications certified under this standard are compliant with X/Open and Spec 1170, and will run on PowerPCs under any PowerOpen-compliant operating system. X Windows, Motif, DOS, Windows, and Macintosh applications can be run in a PowerOpen Environment.

Visit the PowerPoint Web page.

PowerShare

Server software from Apple for Macintosh workgroups and enterprise networks. PowerShare provides messaging and authentication services.

Powersoft Corporation

A Concord, Massachusetts, company that developed the PowerBuilder application development system. Powersoft merged with Sybase in 1995, becoming an independent subsidiary.

PowerTalk

Apple's secure messaging software that uses the AppleTalk transport protocol. PowerTalk is included in the Macintosh operating system beginning with System 7 Pro.

PPC

PowerPC. A family of high-performance RISC microprocessors developed by Apple Computer, Motorola, and IBM (the PowerPC Alliance). The PowerPC processors are designed to emulate other CPUs, so a PowerPC can run DOS and Macintosh as well as other software. These chips are have the speed of the Pentium but use less power. PowerPC architecture is based on the POWER CPU chip, used in IBM RS/6000 workstations. The 601 is a 32-bit microprocessor with a 64-bit bus. The 603 is a 32-bit microprocessor with a 64-bit bus, with low power consumption for use in portable computers. The 620 is a 64-bit microprocessor with a 64-bit bus.

PPD file

PostScript Printer Description File. A file that gives the PostScript driver information about a printer.

pph

Pages per hour. A measurement of printer speed.

ppi

Pixels per inch. A measurement used in bitmap graphics.

ppm

Pages per minute. A measurement of printer speed.

PPN

Project-Programmer Number. Same as user ID. The term comes originally from the TOPS-10 operating system, used on the DEC PDP-10 computers.

PPP

Point to Point Protocol. A protocol for communication between computers using TCP/IP, over standard telephone lines, ISDN, and other high-speed connections. PPP was developed by the Internet Engineering Task Force (IETF) and is defined in RFC 1171. It can be used to connect a computer to the Internet, for services such as the World Wide Web and email. PPP is faster than SLIP and has better error correction; it can be used with both synchronous and asynchronous transmission.

PPS

Polygons Per Second. A measurement of 3D graphics performance by drawing speed.

pps

Packets per second. The measurement of transmission speed in a local area network.

PPTP

Point-to-Point Tunneling Protocol. A version of PPP (Point-to-Point Protocol) that has the ability to encapsulate packets of data formatted for one network protocol in packets used by another protocol. This tunneling technique allows TCP/IP data to be transmitted over a non-TCP/IP network. PPTP can be used to join different physical networks using the Internet as an intermediary.

PQS

Picture Quality Scale. A way of measuring the quality of an image by how well it is perceived by the human eye, instead of measuring differences in pixels as perceived by the computer.

PR

1. Packet Radio. The transmission of data packets between computers by means of amateur radio. Packet radio provides electronic mail, BBS service, chat, file transfer, and games. 2. Proposed Recommendation. W3C’s term for a recommendation before it is officially approved.

Praetor

An advanced plug-in for Microsoft Exchange, from Computer Mail Services (CMS), that proactively blocks spam email. Praetor provides anti-spam filtering by validating all incoming email at both the SMTP (Simple Mail Transfer Protocol) and message levels, thus serving as a comprehensive messaging firewall.

Pragmatic General Multicasting

(PGM). One of two transport protocols used for general multicasting.

PRAM

Parameter RAM. A kind of random access memory that holds basic settings for the Macintosh such as control panels and the desktop. It is refreshed by a battery when the computer is off. The PRAM can be cleared by holding down the option and command keys while booting the computer.

pre-HTML

(phtml). Some HTML documents have embedded equations or other material not expressible in HTML. To embed the non-HTML data, preprocessing instructions (PPIs) are used. Using a program called phtml, the document is then translated into a new HTML document with the equations included as inline pictures. These HTML documents with PPIs have the file extension .PHTML.

Precision Graphics Markup Language

(PGML). A two-dimensional, scalable graphics language for increasing the ease and precision with which graphic images can be produced and integrated into documents. PGML is an application of XML, and PGML graphics can be modified with style sheets along with the XML documents that contain them.

preemptive multitasking

A type of multitasking where the computer or operating system can interrupt a currently running task in order to run another task, as needed. An example would be when a program is running in the foreground and a network transmission is proceeding in the background. The operating system can allot a time slice to each task depending on its priority or the amount of resources it requires. In contrast is cooperative (non-pre-emptive) multitasking, in which it is the applications that decide when to turn over the processor to each other. Mainframes use pre-emptive multitasking, as do the UNIX, OS/2, and Amiga systems.

preference settings

A set of options within a program that the user can choose; for example, in a World Wide Web browser there are options for an email signature file, color and style of text, etc.

preferences

A menu within a program that allows the user to tailor the program to individual needs. The preferences menu can be used to set up views, pagination, mouse tracking, brush styles, default fonts, dictionaries, email signatures, and many other parameters, depending on the program.

PReP

PowerPC Reference Platform. Also called Common Hardware Reference Platform (CHRP). An open system standard for PowerPCs. It allows PowerPC-based computers to run different operating systems, including MacOS, WorkplaceOS, AIX, OS/2, Solaris, Taligent, and Windows NT. It designates ports and sockets for compatibility across platforms, and can be used with various buses.

prepress

The preparation of camera-ready materials for printing. Prepress includes typesetting, page layout, and proofreading.

presentation graphics

The use of computers to create graphic presentations for business and education. Presentation programs such as Freelance Graphics from Lotus or Hollywood from IBM have tools for drawing and painting, and can make charts using data from a spreadsheet. On the computer, the images can be viewed in sequence or as a page of miniature frames, and adapted to a common color scheme. The images can be presented on video, as a slide show with an overhead projector or 35-mm slides, or as a computer screen show. Advanced programs provide special effects such as fades or animation and sound.

presentation layer

Layer 6 of the Open Systems Interconnection (OSI) networking model, which defines file and file access formats, performs file compression, establishes a common syntax between hosts, and converts data so incompatible systems can communicate with each other.

presentation program

A program used to plan, organize, and design business or educational presentations, using drawings, charts, and text. Examples are Aldus Persuasion and PowerPoint from Microsoft. The graphics created are usually displayed as slide shows or videos. See presentation graphics.

Pretty Good Privacy

(PGP). An encryption program based on RSA (Rivest-Shamir-Adleman) public-key cryptography. PGP allows users to exchange files and messages, with both privacy and authentication, over all kinds of networks. The messages are unreadable unless the receiver has an encryption key. PGP encrypts data using the IDEA (International Data Encryption Algorithm) with a randomly generated key, then encrypts the key using the receiver's public key. After the message is transmitted, PGP uses the receiver's private RSA key to decrypt the IDEA key, then decrypts the message using that key. PGP features keys longer than 128 bits, and can be used with UNIX, DOS, Windows, and Mac. Because PGP is based on public-key cryptography, no secure channels are needed to exchange keys between users. PGP can also provide digital signatures for files or messages. Free versions of PGP can be downloaded from various BBS and Internet sources. Commercial versions are available from Viacrypt.

pretzel key

The Macintosh command key, which has a pretzel-shaped logo on it.

preventive maintenance

(PM). Regular inspection of computer hardware to prevent problems before they happen.

preview

A feature in some programs (for example, word processing and drawing programs) that shows on the screen how a document will look when printed. In WYSIWYG programs the file always shows how it will look when printed, so it is unnecessary to switch to a preview mode. A word processing program, however, shows only the text that will be printed and the page breaks, and it is necessary to switch to preview mode to see the overall look of the page, with margins, page numbers, etc.

PRI

Primary Rate Interface. Highest-speed ISDN service.

Primary Key

Used in database management systems as a key field that holds a unique value.

Primary Rate Interface

(PRI). A high-speed ISDN connection (1.544 megabits/second) which can provide voice, data, or video; the equivalent of a T1 line.

primary storage

The internal memory of a computer; Random Access Memory.

Prime Computer

A manufacturer of minicomputers.

prime time

The hours when a network or time-sharing system has the highest number of users logged on.

Primenet, Inc.

A major Internet service provider in Arizona.

print ball

The metal ball-shaped print head on a ball printer.

print buffer

The computer can send data to the printer faster than the printer can print. The print buffer is an area of memory in a printer that stores output from the computer until it can be printed. If the buffer gets full, the computer must wait before it can send more data. If a printer has more than one computer hooked to it, the print buffer will hold the output from one computer while it prints output it received earlier. Also called printer buffer.

print head

In a printer, the mechanism that deposits the ink onto the paper.

print merge

Merging data from one file into another file for printing; for example, printing many copies of a form letter, with a different name and address on each letter. The names and addresses are from a separate database file.

print queue

A lineup of items waiting to be printed.

print screen

A command that prints out whatever appears on the computer screen.

print server

A computer in a network that handles printing for other computers. It may control more than one printer. The other computers send their files to the print server, and the print server sends each file to be printed when a printer is ready.

printer buffer

The computer can send data to the printer faster than the printer can print. The printer buffer is an area of memory in a printer that stores output from the computer until it can be printed. If the buffer gets full, the computer must wait before it can send more data. If a printer has more than one computer hooked to it, the printer buffer will hold the output from one computer while it prints output it received earlier. Also called print buffer.

printer cable

A cable that connects a printer to a computer.

printer control language

PCL. The control language for HP LaserJet printers, also supported by many other printers and typesetting machines. PCL tells the printer how to print a page, as does a page description language.

printer driver

A software routine that describes the physical characteristics of a particular printer, and converts data for printing into a form that printer can understand.

printer engine

The mechanism within a printer that does the actual printing, not including the computer circuitry that controls it.

printer font

A font that gives the printer instructions on how to print each character, rather than a font used to display characters on the computer screen.

printer port

A port for attaching a printer to the computer.

printer queue

A list of items waiting to be output to the printer when the printer is available.

printout

A printed copy of a file; a hard copy.

Privacy Enhanced Mail

(PEM). Electronic mail with confidentiality, authentication, and message integrity.

private automatic branch exchange

(PABX ). A private automatic telephone exchange that allows calls within the exchange and also calls to and from the public telephone network.

private automatic exchange

(PAX). A private automatic telephone exchange that allows calls only within the exchange and not calls to or from the public telephone network.

private branch exchange

(PBX). A telephone exchange used within an organization and located on the premises; an example would be the main switchboard in a hospital.

private file

A file which has very restricted access, perhaps only available to the person who created it.

Private File

A drag-and-drop 128-bit encryption and compression program from Aladdin Software, available for Mac and Windows, which can be integrated into email programs. Encrypted files sent by email can be opened by a receiver who has the password.

private key cryptography

A form of cryptography in which sender and receiver have the same key or similar keys.

private key encryption

A form of cryptography in which sender and receiver have the same key or similar keys.

private management domain

(PRMD). A private, inhouse email service that uses the X.400 protocol.

PRMD

Private Management Domain. A private, inhouse email service that uses the X.400 protocol.

Pro Photo CD

A Photo CD format which can be used to store images from professional format film.

problem-oriented language

A programming language created to address a certain kind of problem; for example, SQL is for database queries, COBOL is for business applications, and FORTRAN was created for scientific problems.

process scheduling

The scheduling of tasks in a multitasking environment, which involves assigning starting and ending times to each task.

processor cache

An area of high-speed memory linked directly to the CPU. The CPU can access information in the processor cache much more quickly than information stored in main memory. Frequently-used data is stored here.

Prodigy

An online information service developed by IBM and Sears. For a monthly fee, users get Internet access, electronic mail, weather and stock market reports, airline scheduling, email, discussion groups, games, and home shopping.

production-level video

(PLV). Very high-quality video compression, used in Digital Video Interactive technology.

productivity suite

A suite of business applications that usually includes a word processing program, a spreadsheet, a database program, a communications program, and a presentation graphics program. Examples would be Claris Works or Microsoft Office.

Professional Office System

(PROFS). An IBM office software and messaging system used mostly on mainframe computers.

PROFS

Professional Office System. An IBM office software and messaging system used mostly on mainframe computers.

prog

Program. This abbreviation is mainly used by hackers for independently created programs rather than large commercial applications; it can indicate a useful program or a harmful one.

proglet

A very short computer program written for some immediate, short-term use.

program maintenance

Updating programs from time to time to keep abreast of changes in an organization's needs or its hardware and software.

programmable

Able to be programmed; able to be given instructions.

Programmable Read Only Memory

(PROM). A memory chip that can only be programmed once. Unlike ROM, which is programmed by the manufacturer, PROM is programmed by the user. See also ROM, EPROM and EEPROM.

programmed input/output

(PIO). Data transfer between two devices in which the data path goes through the computer's main processor. The speed of data transfer corresponds with the PIO mode: PIO mode 0 has a speed of 3.3 MBps; mode 1 is 5.2 MBps; mode 2 is 8.3 MBps; mode 3 is 11.1 MBps; mode 4 is 16.6 MBps.

programmer

A person who writes instructions (programs) for computers.

programmer analyst

A combination programmer and systems analyst.

Programmers Hierarchical Interactive Gra

(PHIGS). An ANSI and ISO standard for a device-independent application programming interface used with two- and three-dimensional graphics applications in high-performance workstations.

programming

Designing and writing a computer program. The programmer must decide what the program needs to do, develop the logic of how to do it, and write instructions for the computer in a programming language that the computer can translate into its own language and execute.

project-programmer number

(PPN). Same as user ID. The term comes originally from the TOPS-10 operating system, used on the DEC PDP-10 computers.

PROM

Programmable Read Only Memory. A memory chip that can only be programmed once. Unlike ROM, which is programmed by the manufacturer, PROM is programmed by the user. See also ROM, EPROM and EEPROM.

promiscuous mode

A networking mode in which a station on a network will accept all packets, no matter what their destination address is.

promiscuous security policy

A policy of allowing everyone access from the Internet to an organization's internal network.

prompt

A message from the computer that asks the operator to do something, such as enter a command, enter a password, or enter data. An example is the DOS prompt, C:.

propagate

To move through a medium; to spread.

propagation

Movement through a conductive medium.

propagation delay

The time required for a signal to travel from one point to another.

propeller head

Somebody who wears a beanie cap with a propeller on top that turns in the breeze. Whether the person literally wears such a cap or not, this term is used to describe a person as a geek.

propeller key

The Macintosh feature key, which has an icon that looks somewhat like a propeller.

proportional-pitch type

Pitch is the number of characters per inch in a given typeface. In fixed-pitch type, every character has the same width; in proportional-pitch type, some characters are wider than others, for the sake of style. For example, an M would be wider than an I. In proportional-pitch type the pitch must be measured as an average of many character widths.

Proposed Recommendation

(PR). W3C’s term for a recommendation before it is officially approved.

proprietary software

Software that is owned by an individual or a company. To use the software, one must purchase a license.

protected mode

A mode in which Windows reserves memory for itself. By switching the microprocessor to this mode, Windows can execute several programs at once, transcending the 1-megabyte limit normally enforced on the processor.

protocol

1. Often simply referred to as a protocol, a communications protocol is a set of rules or standard designed so that computers can exchange information with a minimum of errors.See also Open Systems Interconnection Model (OSI). 2. Layer 3 of the OSI networking model, which handles data routing and addressing.

protocol converter

A device used to translate between protocols.

protocol stack

A hierarchy of protocols which work together to provide the services on a communications network. The OSI seven-layer model, SNA, and TCP/IP are examples.

protocols

Sets of rules that regulate the way data is transmitted between computers. Examples are PPP, TCP, IP, RIP, POP, SNMP, SMTP, SLIP, ARP, RARP, PAP.

proxy ARP

Using one machine to respond to ARP (Address Resolution Protocol) requests for another machine. The proxy machine routs transmission packets to the proper destination.

proxy server

A server that provides access to files from other servers by retrieving them either from its local cache or from the remote server.

prudent security policy

A security policy which disallows access from the Internet to an organization's internal network, except for traffic which is specifically allowed.

PS/2 port

A port available on most PCs that can be used to plug in a mouse or keyboard. It has a socket for a 6-pin mini-DIN plug. The PS/2 port is sometimes called the mouse port.

pseudo compiler

A compiler that generates an intermediate language, called a pseudo language, which must then be compiled or interpreted before execution. The purpose of the pseudo compiler is to make it possible to use the same source language on different types of computers.

pseudo language

An in-between language which is generated from a source language, but must be further compiled or interpreted before it can be executed. The purpose of the pseudo language is to make it possible to use the same source language on different types of computers.

pseudocode

A series of statements that outline what a computer program will do, without putting in the actual programming code. The pseudocode, which can be written in natural language, is a preliminary step in designing a program, and helps the programmer think through what steps will be necessary. At the pseudocode stage, it is not necessary to know what programming language will be used. In a later step, the pseudocode will be translated into actual computer instructions.

pseudosuit

A suit wannabee, or someone posing as a suit for the purpose of making more money. See suit.

PSN

Packet Switch Node. A dedicated computer which routes packets for a packet-switched network.

PSP

Payphone Service Provider.

PSTN

(Public Switched Telephone Network). A voice and data communications service for the general public which uses switched lines.

psychedelicware

Software which makes pretty moving pictures and patterns on the computer display screen.

ptc

A translator program which converts Pascal to C.

PTN

Public Telephone Network. A voice and data communications service for the general public which uses switched or non-switched lines.

PTT

Postal, Telegraph, and Telephone. The government agency that oversees postal, telegraph, and telephone services in some European countries.

public domain

(PD). Belonging to the public; not protected by copyright.

public domain software

Software which has no copyright protection and can be used or copied by anyone free of charge. Sometimes programmers create software and donate it for the good of the general public.

public file

A file which is available to all users accessing a network or system.

public key cryptography

A form of cryptography in which each user has a public key and a private key. Messages are sent encrypted with the receiver's public key; the receiver decrypts them using the private key. Using this method, the private key never has to be revealed to anyone other than the user.

public switched telephone network

(PSTN). A voice and data communications service for the general public which uses switched lines.

public telephone network

(PTN). A voice and data communications service for the general public which uses switched or non-switched lines.

public-key encryption

A way of encrypting messages in which each user has a public key and a private key. Messages are sent encrypted with the receiver's public key; the receiver decrypts them using the private key. Using this method, the private key never has to be revealed to anyone other than the user.

pubnet

Top-level newsgroup category for public access systems newsgroups.

puck

A device used to draw on a digitizer tablet.

puff

To decompress data that has been compressed by Huffman code. See huff.

pull

The opposite of push technology; the user decides to visit a web page or to download software rather than signing up for a service that automatically brings it to the user’s desktop.

pull-down menu

A menu that expands downward when its title is selected with the mouse. A list of options appears as long as the mouse button is held down, and the user can select an option by scrolling through the menu and releasing the mouse button when the desired option is highlighted.

pulled

User-initiated rather than automatic (pushed); for example, a download of software that is initiated by the user rather than pushed by an automated distribution system.

pulse level device

A device whose input and output are in the form of voltages. Contrast bit level device.

punch card

A thin cardboard card which can be punched with hole patterns that represent data.

punch tape

A storage medium used in the early 1900s, following the use of punch cards. Data was stored by means of patterns of holes punched in the paper tape.

punched card

An early data storage method, almost obsolete, in which thin cardboard cards are punched with holes that represented binary information. Punched cards were used with mechanical looms before the invention of computers.

punched tape

Paper tape with holes punched in it to represent data, including program instructions.

punter

A program that sends a user a very large HTML file by email, causing the user's computer to stall or freeze as it waits for the large file to download.

purge

To delete both a set of data and all references to the data.

Purple

An electric rotor cipher machine, modeled after the German Enigma machine, that was used to generate codes for the Japanese during World War II. "Purple" was the American name for the machine.

Purveyor

A World Wide Web server used with Windows NT and Windows 95.

push

1. To put something onto a stack. 2. To deliver data and services to a user’s desktop by means of push technology.

push code

To write the code for a computer program.

push technology

Internet technology that allows information to be delivered or “pushed” directly to a user who subscribes to it, rather than the user having to go look for the information on an Internet site. For example, PointCast, Yahoo, and other services provide news to users who can customize their news reports, choosing from categories such as sports, world news, stock market, etc. and entering their preferences into a database. The news and other chosen services are pushed to the user's computer by means of a web browser or other client software.

pushed

Supplied by means of push technology.

put

An FTP command to copy a file from the local computer to the remote computer.

PVC

Permanent Virtual Circuit. A point-to-point connection that is established in advance. A PVC which is defined at the time of subscribing to a service is called a VPN (virtual private network). Contrast with SVC.

pwd

A UNIX command that indicates what the current working directory is on the virtual server.

PWR

Power On. A modem status signal indicated by a light on the modem, which tells the user the power is on.

PWS

(Pass Word Stealer). A program embedded in a file to steal passwords. The user becomes vulnerable upon downloading the file. The next time the user logs on, the user's password is sent to the maker of the program, without the user's knowledge.

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