Glossary of Computer Terms—P

Glossary of Computer Terms—P

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PALM: A hand-held computer.

PASCAL: A high-level programming language that is structured to encourage efficient programming habits (documentation) and is used extensively in educational institutions and engineering environments.

PARALLEL OPERATION: A method of data transmission in which all bits of a digital word are handled simultaneously with each bit on a separate line. Although faster and simpler to install and operate than SERIAL OPERATION, this method requires more transmission lines (real estate).

PARITY: A method of verifying the accuracy of binary data after it has been transferred to or from a storage area.

PARTITION: A portion of a hard disk that functions as a separate unit. A single hard disk can be divided into several partitions, each of which functions as a separate drive and has its own volume name (such as D:, E:, F:, and so on). The purpose is to make the drive more efficient, as the computer can search smaller sections for a specific file rather than the entire drive. The verb to partition refers to the process of dividing the hard drive into partitions.

PC BOARD: Printed Circuit board. A board printed or etched with a circuit and processors. Power supplies, information storage devices, or changers are attached.

PCMCIA (PERSONAL COMPUTER MEMORY CARD INTERNATIONAL ASSOCIATION): A package in a plastic card form containing semiconductor memory, particularly FLASH. These cards are plugged into the card slot in laptop computers.

PDA: Personal Digital Assistant. A hand-held computer that can store daily appointments, phone numbers, addresses, and other important information. Most PDAs link to a desktop or laptop computer to download or upload information.

PDF: Stands for Portable Document Format. A technology developed by Adobe and was designed to capture all of the elements of a printed document and place it in a singe image file. This PDF file can be navigated, printed or attached to an email for sharing. In order to be able to view a PDF file on your computer, you will need to download and install the free Acrobat Reader. Once installed, anytime a PDF file is clicked, the image file will automatically be viewed.

PEER TO PEER: A type of network in which each workstation has equivalent capabilities and responsibilities. This differs from client/server architectures, in which some computers are dedicated to serving the others. Peer-to-peer networks are generally simpler and less expensive, but they usually do not offer the same performance under heavy loads.

PEN DRIVE: A small keyring-sized device that can be used to easily transfer files between USB-compatible systems. Available in a range of capacities (and in some cases, with an MP3 player built-in). Plug it in to any USB port and it will be automatically detected by the Operating System.

PENTIUM CHIP: Intel’s fifth generation of sophisticated high-speed microprocessors. Pentium means “the fifth element.”

PERIPHERAL: A term designating the various kinds of machines and devices that work in conjunction with a computer but are not necessarily part of the computer structure. Typically, peripherals refer to: printers, keyboards, monitors, scanners, CD ROM drives, and plotters. A hard drive, floppy disk drive, and a MODEM are considered to be peripheral devices even though they may be physically located inside a computer.

PERSONAL COMPUTER (PC): A single-user computer containing a central processing unit (CPU) and one or more memory circuits.

PETABYTE: A measure of memory or storage capacity and is approximately a thousand terabytes.

PETAFLOP: A theoretical measure of a computer’s speed and can be expressed as a thousand-trillion floating-point operations per second.

PICT: Pronounced “Pick,t.” It is another image format.

PLATFORM: The operating system, such as UNIX®, Macintosh®, Windows?, on which a computer is based.

PLUG-IN: This is a program that your browser uses to manipulate a downloaded file. It differs from a Helper Application in that the plug-in works inside the browser window.

PLUG AND PLAY: Computer hardware or peripherals that come set up with necessary software so that when attached to a computer, they are “recognized” by the computer and are ready to use.

PLUG-COMPATIBLE: A term that describes the ability of peripherals to be interchanged without modification.

POLLING: A process in which a number of peripheral devices, remote stations, or nodes in a computer network are interrogated, one at a time, to determine if service is required.

POP (Post Office Protocol): An Internet protocol that enables a single user to read e-mail from a mail server.

POP (Point of Presence): A site that has an array of telecommunications equipment: modems, digital, leased lines and Internet routers. An Internet access provider may operate several regional PoPs to provide Internet connections within local phone service areas. An alternative is for access providers to employ virtual PoPs (virtual Points of Presence) in conjunction with third party provider.

POP-UP MENU: A menu window that opens vertically or horizontally onscreen to display context-related options. Also called drop-down menu or pull-down menu.

PORT: An input/output channel (either parallel or serial), terminated at a connector on the computer. It interconnects the computer’s input and/or output terminals to an appropriate source and/or destination.

PORTRAIT: A term that designates the position of conventional printing across the width of a page.

POSITIVE LOGIC: This logic represents the reverse of NEGATIVE LOGIC. It is the more commonly used form of logic. A positive voltage represents a “1” state and a negative (or zero) voltage represents a “0” state.

POWER PC: A competitor of the Pentium chip. It is a new generation of powerful sophisticated microprocessors produced from an Apple-IBMMotorola alliance.

PPP: Stands for Point To Point Protocol. It’s a software application that allows an attachment to a server.

PRINT SPOOLER: A device for temporarily storing data to be printed when the printer is functioning. It provides uninterrupted data entry and editing while the printer is active and while other data awaits transmission to the printer.

PRINTER: A mechanical device for printing a computer’s output on paper.

PROGRAM: A complete sequence of computer software instructions necessary to provide an application, solve a specific problem, perform an action, or respond to external stimuli in a prescribed manner. As a verb, it means to develop a program.

PROGRAM COUNTER (PC): A special-purpose register in the CPU which contains the address of the next instruction to be fetched and executed. PROGRAMMABLE LOGIC ARRAY (PLA): An unprogrammed, generalpurpose logic structure in monolithic IC form consisting of an array of similar, and/or compatible logic gates. Also called PROGRAMMABLE ARRAY LOGIC (PAL).

PROGRAMMABLE READ-ONLY MEMORY (PROM): A blank read-only memory (ROM) that is programmed with external programming equipment after manufacture. Once programmed, it is not re-programmable and is considered to be a ROM.

PROGRAMMING LANGUAGE: A series of instructions written by a programmer according to a given set of rules or conventions (“syntax”). High-level programming languages are independent of the device on which the application (or program) will eventually run; low-level languages are specific to each program or platform. Programming language instructions are converted into programs in language specific to a particular machine or operating system (“machine language”) so that the computer can interpret and carry out the instructions. Some common programming languages are BASIC, C, C++, dBASE, FORTRAN, and Perl.

PROPAGATION DELAY: The time required for the output of a logic gate to respond to a combination of input pulses.

PROTOCOLS: Computer rules that provide uniform specifications so that computer hardware and operating systems can communicate. It’s similar to the way that mail, in countries around the world, is addressed in the same basic format so that postal workers know where to find the recipient’s address, the sender’s return address and the postage stamp. Regardless of the underlying language, the basic “protocols” remain the same.

PROXY-SERVER: A server that acts as an intermediary between a workstation user and the internet so that the enterprise can ensure security, administrative control, and caching service. A proxy server is associated with, or part of, a gateway server that separates the enterprise network from the outside network and a firewall server that protects the enterprise network from the outside intrusion.

PUCK: An input device, like a mouse. It has a magnifying glass with crosshairs on the front of it that allows the operator to position it precisely when tracing a drawing for use with CAD-CAM software.

PULL-DOWN MENU: A menu window that opens vertically on-screen to display context-related options. Also called drop-down menu or pop-up menu.

PUSH: The instruction used to deposit a word on top of a stack.

PUSH-DOWN STACK: A dedicated temporary storage register in a computer, sometimes part of a system memory, structured so that data (words) in the stack are retrieved in reverse order of entry. See LIFO. 
PUSH TECHNOLOGY: Internet tool that delivers specific information directly to a user’s desktop, eliminating the need to surf for it. PointCast, which delivers news in user-defined categories, is a popular example of this technology.