P2P

Peer-to-Peer, is a decentralized communications model in which each party has the same capabilities and either party can initiate a communication session.

Packet

Any information sent over a network is divided into chucks of data called packets, which are then routed. Additional bits are added to the information, such as address of the sender and receiver, error control information and check procedures, to ensure that the right information gets to where it has been requested to goto in the correct form.

PAN

Personal Area Network is an IBM technology that allows individuals to exchange data via a receiver and transmitter. It is based on the electric-field transmission medium.

PAP

Password Authentication Protocol. In PPP networks, a method of validating connection requests.

Pascal

Pascal is an imperative and procedural programming language, published in 1970.

PAT

Port Address Translation, a type of network address translation (NAT). During PAT, each computer on LAN is translated to the same ip address, but with a different port number assignment. PAT is also referred to as overloading, port mapping, port-level multiplexed NAT or single address NAT.

Patch

A software upgrade that corrects a programming problem. Also known as a Fix.

PCB

(1) Printed Circuit Board.
(2) Process Control Block, is a data structure in the operating system kernel containing the information needed to manage the scheduling of a particular process.

PCH

Platform Controller Hub is a family of Intel chipsets, introduced circa 2008.

PCI

Peripheral Component Interconnect, a local bus standard developed by Intel. Most modern PCs include a PCI bus in addition to a more general ISA expansion bus. Many analysts, however, believe that PCI will eventually supplant ISA entirely. PCI is also used on newer versions of the Macintosh computer.
PCI is a 64-bit bus, though it is usually implemented as a 32-bit bus. It can run at clock speeds of 33 or 66 MHz. At 32 bits and 33 MHz, it yields a throughput rate of 133 MBps.

PCL

Printer Control Language, the page description language ( PDL) developed by Hewlett Packard and used in many of their laser printer and ink-jet printers. PCL 5 and later versions support a scalable font technology called Intellifont.

PCM

(1) Pulse-Code Modulation is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications.
(2)Power-train Control Module, abbreviated PCM, is an automotive component.

PCMCIA

Personal Computer Memory Card International Association, is an organization consisting of some 500 companies that has developed a standard for small, credit card-sized devices, called PC Cards. Originally designed for adding memory to portable computers, the PCMCIA standard has been expanded several times and is now suitable for many types of devices. There are now three types of PCMCIA cards.
In general, you can exchange PC Cards on the fly, without rebooting your computer.

PCS

Personal Communications Service, describes a set of digital mobile phone technologies being deployed in the U.S. PCS is a second generation mobile communications technology.

PDA

Personal Digital Assistant, a handheld device that combines computing, telephone/fax, and networking features. Most PDAs are pen-based, rather than keyboard based for input.

PDL

Page Description Language. A language for describing the layout and contents of a printed page. The best-known PDLs are Adobe PostScript and Hewlett-Packard PCL (Printer Control Language), both of which are used to control laser printers.

PEBKAC

Problem Exists Between Keyboard And Chair, is a term used by computer technicians and IT professionals to describe a user error.

Pentest

Short for penetration test. An authorised test of a computer network or system designed to look for security weaknesses so that they can be fixed.

PERL

Practical Extraction and Report Language, Perl is a programming language especially designed for processing text. Because of its strong text processing abilities, Perl has become one of the most popular languages for writing CGI scripts. Perl is an interpretive language, which makes it easy to build and test simple programs.

Petabyte

A unit of 2 to the power 50 byte or 1024 terabytes.

Petaflop

A unit of computing speed equal to one thousand million million floating-point operations per second.

Petascale

In computing, petascale refers to a computer system capable of reaching performance in excess of one petaflop.

PGA

(1) Pin Grid Array, a type of chip package in which the connecting pins are located on the bottom in concentric squares. PGA chips are particularly good for chips that have many pins, such as modern microprocessors.

(2) Professional Graphics Adapter, a video standard developed by IBM that supports 640x480 resolution

PGP

Pretty Good Privacy. A technique for encrypting messages. PGP is one of the most common ways to protect messages on the Internet because it is effective, easy to use, and free. PGP is based on the public-key method, which uses two keys -- one is a public key that you disseminate to anyone from whom you want to receive a message. The other is a private key that you use to decrypt messages that you receive. To encrypt a message using PGP, you need the PGP encryption package, which is available for free from a number of sources.

Phishing

A scam where the perpetrator sends out legitimate-looking e-mails appearing to come from some of the Web's biggest sites in an effort to phish for personal and financial information from the recipient. Phishers use any number of different social engineering and e-mail spoofing ploys to try to trick their victims.

PHP

(1) Personal Home Page.

(2) PHP Hypertext Preprocessor is a server-side, HTML embedded scripting language used to create dynamic Web pages. In an HTML document, PHP script (similar syntax to that of Perl or C ) is enclosed within special PHP tags. Because PHP is embedded within tags, the author can jump between HTML and PHP instead of having to rely on heavy amounts of code to output HTML. And, because PHP is executed on the server, the client cannot view the PHP code. PHP can perform any task any CGI program can do, but its strength lies in its compatibility with many types of databases. Also, PHP can talk across networks using IMAP, SNMP, NNTP, POP3, or HTTP.

Phreaking

Closely related to hacking, using a computer or other device to trick a phone system. Typically, phreaking is used to make free calls or to have calls charged to a different account.

PIN

Personal Identification Number

PINN

Physically Independent Neural Network, an AI charactor in film Transcendence

PLA

Polylactic Acid, is one of two common plastics used on FDM 3D printing machines.

Platform

The basic hardware (device) and software (operating system) on which applications can be run.

PLC

Programmable Logic Controller, which are divided into three types based on output, namely Relay output, Transistor output, and Triac Output.

PLED

Polymer, or polymeric, light-emitting diode, a backlighting, illumination and display technology.

Pleiades

Pleiades is a petascale supercomputer housed at the NASA Advanced Supercomputing facility at NASA Ames Research Centre located at Moffett Field near Mountain View, California.

Plug and Play

Refers to the ability of a computer system to automatically configure expansion boards and other devices. You should be able to plug in a device and play with it, without worrying about setting DIP switches, jumpers, and other configuration elements. Since the introduction of the NuBus, the Apple Macintosh has been a plug-and-play computer. The Plug and Play (PnP) specification has made PCs more plug-and-play, although it doesn't always work as advertised. see face="Times New Roman" size="-1" color="#0000FF">Plug and Pray

Plug and Pray

Slang for Plug and Play, due to the problems of the devices automatically configuring themselves to conflict with other devices and to change configuration each time the PC was rebooted.

Plug-in

A hardware or software module that adds a specific feature or service to a larger system. For example, there are number of plug-ins for the Netscape Navigator browser that enable it to display different types of audio or video messages. Navigator plug-ins are based on MIME file types.

PMU

Power Management Unit, is a microcontroller that governs power functions of digital platforms.

Polyline

In computer graphics, a continuous line composed of one or more line segments. You can create a polyline by specifying the endpoints of each segment. In draw programs, you can treat a polyline as a single object, or divide it into its component segments.

PON

Passive Optical Network, is a high bandwidth point to multipoint optical fiber network based on the ATM protocol. PONs are capable of delivering high volumes of bandwidth, which can be changed on-the-fly depending on an individual user's needs.

POP

(1) Short for Post Office Protocol, a protocol used to retrieve e-mail from a mail server. Most e-mail applications (sometimes called an e-mail client ) use the POP protocol, although some can use the newer IMAP.

(2) Point Of Presence, a telephone number that gives you dial-up access. Internet Service Providers (ISPs) generally provide many POPs so that users can make a local call to gain Internet access.

Port

(n) (1) An interface on a computer to which you can connect a device. Personal computers have various types of ports. Internally, there are several ports for connecting disk drives, display screens, and keyboards. Externally, personal computers have ports for connecting modems , printers, mice, and other peripheral devices.

(2) In TCP/IP and UDP networks, an endpoint to a logical connection. The port number identifies what type of port it is. For example, port 80 is used for HTTP traffic.

(v) To move a program from one type of computer to another. To port an application, you need to rewrite sections that are machine dependent, and then recompile the program on the new computer. Programs that can be ported easily are said to be portable.

Portal

A web site that greets users, gives large amount of information on a specific topic and offers links to other related web sites.

POSIX

Portable Operating System Interface for UNIX, a set of IEEE and ISO standards that define an interface between programs and operating systems. By designing their programs to conform to POSIX, developers have some assurance that their software can be easily ported to POSIX compliant operating systems. This includes most varieties of UNIX as well as NT.
The POSIX standards are now maintained by an arm of the IEEE called the Portable Applications Standards Committee (PASC).

POST

(1) (v) To publish a message in an online forum or newsgroup or e-Mail.
(n) A message published in an online forum or newsgroup or e-Mail.

(2) Power-On Self Test. When power is turned on, POST is the diagnostic testing sequence that a computer's basic input/output system (or "starting program") runs to determine if the computer keyboard, random access memory, disk drives, and other hardware are working correctly.

Postscript

A page description language (PDL) developed by Adobe Systems in 1985. PostScript is primarily a language for printing documents on laser printers , but it can be adapted to produce images on other types of device. PostScript is the standard for desktop publishing because it is supported by imagesetters, the very high-resolution printer used by service bureaus. PostScript is an object-oriented language, meaning that it treats images, including fonts, as collections of geometrical object rather than as bit maps.

POTS

Plain Old Telephone Service, which refers to the standard telephone service that most homes use. It is generally restricted to about 52Kbps.
The POTS network is also called the public switched telephone network ( PSTN).

PPC

Pay Per Click, is an internet advertising model used to drive traffic to websites, in which an advertiser pays a publisher when the ad is clicked.

PPGA

Plastic Pin Grid Array. PPGAs were first developed by Intel in 1993 to combat power supply decoupling issues in high-performance microprocessors.This square chip packaging technology was designed for microprocessors with greater numbers of transistors on each chip than previous models.

PPI

Pixels per Inch, is a measure of the sharpness (that is, the density of illuminated points) on a display screen. The dot pitch determines the absolute limit of the possible pixels per inch. However, the displayed resolution of pixels (picture elements) that is set up for the display is usually not as fine as the dot pitch. The pixels per inch for a given picture resolution will differ based on the overall screen size since the same number of pixels are being spread out over a different space. The term "dots per inch" (DPI), extended from the print medium, is sometimes used instead of pixels per inch.

PPP

Point-to-Point Protocol, a method of connecting a computer to the Internet. PPP is more stable than the older SLIP protocol and provides error checking features.

PPPoE

Point-to-Point Protocol over Ethernet. PPPoE relies on two widely accepted standards: PPP and Ethernet. PPPoE is a specification for connecting the users on an Ethernet to the Internet through a common broadband medium, such as a single DSL line, wireless device or cable modem.

PPTP

Point-to-Point Tunneling Protocol, a new technology for creating Virtual Private Networks (VPNs). Because the Internet is essentially an open network, the Point-to-Point Tunneling Protocol (PPTP) is used to ensure that messages transmitted from one VPN node to another are secure. With PPTP, users can dial in to their corporate network via the Internet.

PRI

Primary-Rate Interface, a type of ISDN service designed for larger organisations. PRI includes 23 B-channels (30 in Europe) and 1 D-Channel. PRI service is generally transmitted through a T-1 line (or an E1 line in Europe).
See BRI.

PROM

Programmable Read-Only Memory, is a form of digital memory where the setting of each bit is locked by a fuse or antifuse.

Protocol

An agreed-upon format for transmitting data between two devices. The protocol determines the following:

a) the type of error checking to be used
b) data compression method, if any
c) how the sending device will indicate that it has finished sending a message
d) how the receiving device will indicate that it has received a message

There are a variety of standard protocols from which programmer can choose. Each has particular advantages and disadvantages; for example, some are simpler than others, some are more reliable, and some are faster. From a user's point of view, the only interesting aspect about protocols is that your computer or device must support the right ones if you want to communicate with other computers. The protocol can be implemented either in hardware or in software.

PRSB

Professional Record Standards Boby.

PS/2

Personal System/2, is a 6 pin port used for connecting keyboards ans mice to a computer.

PSTN

Public Switched Telephone Network, which refers to the international telephone system based on copper wires carrying analog voice data.

PSU

Power Supply Unit.

PUE

Power Usage Effectiveness, is a ratio that describes how efficiently a computer data center uses energy; specifically, how much energy is used by the computing equipment.

Pull

To request data from another program or computer.

Pulsing Zombie

A form of DoS attack known as a degradation-of-service attack, as opposed to a denial-of-service attack. Unlike a regular zombie that paralyzes a system by inundating it with a steady stream of attack traffic, the pulsing zombie attacks with irregular small bursts of attack traffic from multiple sources on a single target over an extended period of time. Pulsing zombie attacks are more difficult to detect and trace because since they are slow and gradual they do not immediately appear as malicious.

Pure Play

A dot-com that has no presence on the high street.

Push

(1) In client/server applications, to send data to a client without the client requesting it.
(2) In programming, to place a data item onto a stack.

PWM

Pulse Width Modulation.

Python

An interpreted, object-oriented programming language. Python is very portable since Python interpreters are available for most operating system platforms. Although Python is copyrighted, the source code is freely available, and unlike GNU software, it can be commercially re-sold.