Packet A packet is a piece of data that is sent from one place to another over the Internet or a company's network. More specifically, it's one of many pieces. For example when you send an e-mail message, it has to be divided into "packets" to allow many computers to communicate with each other. If a transmission was not broken up into packets, two computers could "hog" the network with one transmission, therefore other computers from communicating with each other. Once the packets reach their destination, they are reassembled and the message can then be viewed (hopefully intact).
Packet Switching A data transmission technique which segments data into packets and routes them to the desired destination, where the data is re-assembled in the correct order.
Page Relating to video, a page is a part of the video buffer (or memory) that holds data for a single screen.
Palette A set of colours available for selection.
Palette Code A number that corresponds to a particualr colour from the available palette.
Partition An area of the hard drive set aside for a particular use. Sometimes referred to as a volume.
Partition Table A table in the system area of a hard disk that identifies which sectors belongs to which partitions.
PASCAL A programming language that is highly structured, so many use it as a way of teaching programming. In fact, it was developed as an instructional tool in the late '60s. It has been used in business, though not as frequently as other programming languages, simply because it doesn't lend itself to large applications.
Path The logical hierarchy for a file's location is known as its "path." When you're running Windows and have a budget spreadsheet in a data directory, the path to the file would most likely be C:\Data\Budget.xls.
PCI Acronym for "Peripheral Component Interconnect." It provides a communication path between a microprocessor and additional system components with as little system overhead as possible. Most new computers contain PCI interfaces, and many of today's computer peripherals are designed with a PCI interface. The standard was developed by Intel, but it doesn't adhere to any particular microprocessor type, as it's in common use with Intel, AMD, PowerPC and other processor platforms. Also note that most PCI implementations have a 32-bit data path, but there is also a 64-bit version, typically used in high performance servers and workstations.
PCMCIA Personal Computer Memory Card International Association. The body who controls standards for the "credit card" sized cards which can be installed in laptops. Some people say that this is really the acronym for People Can't Memorise Computer Industry Acronyms.
PDL Acronym for Page Description Language.  It is a programming language like PostScript that describes how an image is to be printed.  The target printer must have an interpreter for the PDL used.  The CPU in the printer then processes the PDL commands and prints the desired output.
Peripheral An external device that connects to a computer, eg. printer, scanner, etc.
Petabyte 2 to the 50th power bytes, or roughly 1,000 (actually, 1,024) terabytes--or precisely 1,125,899,906,842,624 bytes.
PGP PGP stands for "Pretty Good Privacy" one of the current standards for encrypting Internet e-mail. Turns out that "pretty good" is actually about as good as encryption software gets--extremely secure, easy to implement, transparent to users, and FREE. In fact, PGP encryption is so hard to crack that the U.S. government actually sued its inventor, Philip Zimmerman, for making it freely available to America's enemies.
Phase-change Printer Also called a "solid ink-jet printer," a phase-change printer is a colour ink-jet printer that melts its ink (which usually begins as a waxy block) before it jets the ink onto the page. Phase-change printers print crisper, smoother colours than do regular ink-jet printers and do so on just about any type of paper or output media. They're also a lot slower and more expensive.
Phishing Phishing attacks use 'spoofed' e-mails and fraudulent websites designed to fool recipients into divulging personal financial data such as credit card numbers, account usernames and passwords, social security numbers, etc. By hijacking the trusted brands of well-known banks, online retailers and credit card companies, phishers are able to convince up to 5% of recipients to respond to them.
Phreak A type of hacker who uses his or her computer to break into a telephone network to either listen in on other people's conversations or make long-distance phone calls for free.
Ping Acronym for "Packet Internet Groper." When you ping, you're seeing if a specific IP address is accessible. A packet is sent, and a reply is sent back (assuming that it is up and running).
Pixel A pixel is a term to describe a single dot on a computer screen. The more dots, or pixels, you have, the better the image on the screen. Computer monitors and graphics cards vary in the number of pixels that they are able to display on a screen at one time. This total number of pixels on a screen is called the resolution.
Platform The word "platform" has been used so ambiguously that it now has several meanings. A platform can refer to a class of computer hardware, such as Intel (used in PCs) or SPARC (used in Sun workstations). It can refer to an operating system, such as Windows NT, DOS, or UNIX. Or it can refer to a combination of the two, such as Intel/DOS.
Plug and Play (PnP) PnP allows you to plug in a peripheral and have the PC or Operating System automatically recognise it. In other words, you don't have to go in and tell the computer that you've just added a new piece of hardware.
Power Supply A computer's power supply does three very important things. First, it takes the required amount of current from the outlet into which the computer is plugged. Second, it converts that current from AC (alternating current, what you get from your wall outlet) to DC (direct current, what you need to run the computer reliably). Third, its built-in surge protection eliminates spikes and surges to some degree but is no substitute for an external surge protector.
Processor see CPU.
Proportional font A proportional font is one in which different letters are different widths, eg. the letter "m" will take up a wider space than the letter "i".  Also, blank spaces can be adjusted to best fit text on the line.
Protocol A set of standards that enables two computers to communicate or transfer data between them. You could also describe a protocol like a spoken language. If such standards did not exist or two computers use different protocol, then they will not be able to communicate with each other over a network or phone line. For example, a computer configured to use the TCP/IP protocol cannot communicate with a server configured to use Novell's IPX protocol.
Public domain software Public domain software is software that's not protected by copyright--not because of some oversight but because the program's creator wants you to feel free to use the software anyway you like. If you're a bread-and-butter user, this means you can use the software for free and give away copies of it to all your friends; if you're a programmer, this means you can actually include the program--or portions of its code--in programs of your own.
Public key infrastructure (PKI) A security infrastructure that uses public and private key pairs to ensure the authentication, integrity and confidentiality of communications. Typically, the public key is stored in a digital certificate.


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This page was last updated on Sunday, 14 December 2008