Stands for Point To Point Protocol. It's a software application that allows
an attachment to a server.
A unit of data formatted to transmit through a network. A packet is sent
from a source to a destination.
- Parallel Port:
A parallel interface for connecting an external device such as a printer.
Most personal computers have both a parallel port and at least one serial
port. On PCs, the parallel port uses a 25-pin connector (type DB-25) and is
used to connect printers, computers and other devices that need relatively
high bandwidth. It is often called a Centronics interface after the company
that designed the original standard for parallel communication between a
computer and printer. (The modern parallel interface is based on a design by
A newer type of parallel port, which supports the same connectors as the
Centronics interface, is the EPP (Enhanced Parallel Port) or ECP (Extended
Capabilities Port). Both of these parallel ports support bi-directional
communication and transfer rates ten times as fast as the Centronics port.
Macintoshes have a SCSI port, which is parallel, but more flexible.
In data communications, this is an data error detection scheme. It deals
with a fact that all numbers have a parity (odd or even, eg: 1 or 0).
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
- Passive Matrix:
An older form of LCD (liquid crystal display) technology that processes
pixels using row-and-column formatting. This type of formatting produces
slower responce times and lower contrast ratios when compared to Active
- Patch Panel:
In networking a patch panel connects all networked computers to the
incoming and outgoing lines of a LAN (Local Area Network) or any other
electronic communications system.
A path can be described as a file's address on your file system, describing
where the file lives: An absolute path gives the complete path, starting at
the root directory, or the very top of the file system; A relative path
looks for a file from the directory you are currently in down.
Acronym for Peripheral Component Interconnect, a local bus standard
developed by Intel Corporation. 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.
Although it was developed by Intel, PCI is not tied to any particular family
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.
Any external device attached to a computer. Examples of peripherals include
printers, disk drives, display monitors, keyboards, and mice.
Short for 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. Compare with DIP and SIP.
Short for Professional Graphics Adapter, a video standard developed by IBM
that supports 640x480 resolution.
Short for Password Harvesting Fishing. It is the luring of sensitive
information, such as passwords and other personal information, from a victim
by masquerading as someone trustworthy with a real need for such
Popular targets are users of online banking services, and auction sites such
as eBay. Phishers usually work by sending out spam e-mail to large numbers
of potential victims. Typically the email will appear to come from a
trustworthy company and contain a subject and message intended to alarm the
recipient into taking action.
A common approach is to tell the recipient that their account has been
de-activated due to a problem and inform them that they must take action to
re-activate their account. The user is provided with a convenient link in
the same email that takes the email recipient to a fake web page appearing
to be that of a trustworthy company. Once at that page, the user enters her
personal information which is then captured by the fraudster.
(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
(similar to ASP and Cold Fusion) instead of having to rely on heavy amounts
of code to output HTML. Because PHP is executed on the server, the client
cannot view the PHP code. PHP can perform any task any CGI program can, 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.
Pronounced "Pick,t." It is another image format.
Packet Internet or Inter-Network Groper; a utility used to determine whether
a particular computer is currently connected to the Internet. It works by
sending a packet to the specified IP address and waiting for a reply. The
computer acronym "PING" was contrived to match the submariners' term for the
sound of a returned sonar pulse.
A diagram or table that describes the purpose of each pin in a chip or
connector, or each wire in a cable.
(Programmed Input/Output) A method of data transfer in which the host
microprocessor transfers data to and from memory via the computer's I/O
ports. PIO enables very fast data transfer rates, especially in
single-tasking operating systems like DOS.
- Pipeline Burst
A type of memory cache built into many modern DRAM controller and chipset
designs. Pipeline burst caches use two techniques - a burst mode that
pre-fetches memory contents before they are requested, and pipelining so
that one memory value can be accessed in the cache at the same time that
another memory value is accessed in DRAM. The purpose of pipeline burst
caches is to minimize wait states so that memory can be accessed as fast a
possible by the microprocessor.
A processor performance enhancement process that allows for a second
instruction to be performed before the first has completed. This process
produces a steady stream of information and greatly increases the
productivity of the processor.
Short for Picture Element, a pixel is a single point in a graphic image.
Graphics monitors display pictures by dividing the display screen into
thousands (or millions) of pixels, arranged in rows and columns. The pixels
are so close together that they appear connected.
The number of bits used to represent each pixel determines how many colors
or shades of gray can be displayed. For example, in 8-bit color mode, the
color monitor uses 8 bits for each pixel, making it possible to display 2 to
the 8th power (256) different colors or shades of gray.
On color monitors, each pixel is actually composed of three dots -- a red, a
blue, and a green one. Ideally, the three dots should all converge at the
same point, but all monitors have some convergence error that can make color
pixels appear fuzzy.
The quality of a display system largely depends on its resolution, how many
pixels it can display, and how many bits are used to represent each pixel.
VGA systems display 640 by 480, or about 300,000 pixels. In contrast, SVGA
systems display 1,024 by 768, or nearly 800,000 pixels. True Color systems
use 24 bits per pixel, allowing them to display more than 16 million
A combination of hardware and operating system you use, for example, the "NT
platform" is a PC running the Microsoft Windows NT operating system and the
"PPC platform" is a Macintosh computer with a PowerPC processor running the
Mac operating system.
(Programmable Logic Device) A digital integrated circuit that can be
programmed by the user to perform a wide variety of logical operations.
A computer output device that draws images on paper using a pen. A plotter
draws real lines rather than simulating them as a conventional printer would
by producing a series of very close dots.
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
Short for Plug and Play, a technology developed by Microsoft and Intel that
supports plug-and-play installation. PnP is built into the Windows 95
operating system, but to use it, the computer's BIOS and expansion boards
must also support PnP.
This is the connecting component or hardware that allows two computers to
attach to one another.
A web site that aims to be an entry point to the World-Wide Web, typically
offering a search engine and/or links to useful pages, and possibly news or
other services. These services are usually provided for free in the hope
that users will make the site their default home page or at least visit it
often. Popular examples are Yahoo and MSN. Most portals on the Internet
exist to generate advertising income for their owners, others may be focused
on a specific group of users and may be part of an intranet or extranet.
Some may just concentrate on one particular subject, say technology or
medicine, and are known as a vertical portals.
Short for power-on self test, a series of diagnostic tests that run
automatically when you turn your computer on. The actual tests can differ
depending on how the BIOS is configured, but usually the POST tests the RAM,
the keyboard, and the disk drives. If the tests are successful, the computer
boots itself. If the tests are unsuccessful, the computer reports the error
by emitting a series of beeps and possibly displaying an error message and
code on the display screen. The number of beeps indicates the error, but
differs from one BIOS to another.
Point of Presence, also Post Office Protocol
Two commonly used meanings:
A Point of Presence usually means a city or location where a network can be
connected to, often with dial up phone lines. So if an Internet company says
they will soon have a POP in Belgrade, it means that they will soon have a
local phone number in Belgrade and/or a place where leased lines can connect
to their network.
A second meaning, Post Office Protocol refers to a way that e-mail client
software, such as Outlook, gets mail from a mail server. When you obtain an
account from an Internet Service Provider (ISP) you almost always get a POP
account with it, and it is this POP account that you tell your e-mail
software to use to get your mail. Another protocol called IMAP is replacing
POP for email.
- Primary Cache:
Primary cache is the cache located closest to the CPU. Usually, primary
cache is internal to the CPU, and secondary cache is external. Some
early-model personal computers have CPU chips that don't contain internal
cache. In these cases the external cache, if present, would actually be the
primary (L1) cache.
- Primary Key:
A set of one or more values in a database that uniquely identifies a record
in a table.
This refers to low-level objects or older older objects that can be
introduced in to a higher-level object to construct a more complex object.
- Proof Theory:
This deals with the actual "logic" of the programming. Using
mathematical analysis techniques, the programming language is proof checked.
A processor is a device that processes programmed instructions and performs
tasks. Your processor sends and receives information from the different
parts of the system (from hardware and software). The speed at which the CPU
processes information internally is measured in MegaHertz (MHz) and
GigaHertz (GHz). 1 GHz is equal to 1,000 MHz.
Read-Only Memory (PROM):
A special memory chip that is blank when first purchased. It can be written
to by the user by using a special hardware programmer. Once the data is
written to it, it cannot be erased or changed.
An agreed-upon format for transmitting data between two devices. The
protocol determines the following:
-The type of error checking to be used.
-Data compression method, if any.
-How the sending device will indicate that it has finished sending a
-How the receiving device will indicate that it has received a message.
There are a variety of standard protocols from which programmers 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.
- 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
- PS/2 Port:
A type of port developed by IBM for connecting a mouse or keyboard to a PC.
The PS/2 port supports a mini DIN plug containing just 6 pins. Most PCs have
a PS/2 port so that the serial port can be used by another device, such as a
modem. The PS/2 port is often called the mouse port.
Pre-boot eXecution Environment. (pronounced "pixie") Created by Intel, it is
one of their WfM specification components. A PXE-enabled workstation has a
jumper that connects its NIC to the LAN which will keep the workstation
connected to the network even when there is no power. Having this installed
jumper, the system administrator will not have to physically visit this
workstation to load software or run diagnostic programs. It is all done over