Technical information

© CLEAPSS 2005 1653 ICT in the Science Department
Operating
system
The system software that provides for the direct control and management of the
computer’s hardware and basic operation. It is the foundation upon which application
programs are run. Abbreviated to OS.
Output The information going out from a computer or other controller. (The same term is
sometimes used for the connection through which the information flows.)
PAL Phase Alternating Line. The format in which TV signals are encoded in the UK.
Alternative formats are NTSC (eg, in the USA) and SECAM (eg, in France).
Palmtop See PDA.
Parallel port Socket on a computer for connecting a printer or other ‘parallel’ devices.
Parallel
transmission
The transfer of signals over a group of separate connections, simultaneously.
Parameter A value or piece of data that is passed to a program, procedure, macro, routine or
function that defines its action or specifies a value to be evaluated.
PATA Parallel Advances Technology Attachment. Often simply referred to as ATA. Current IDE
drives use PATA. SATA is the new standard for connecting hard drives.
Path In file storage, the route the operating system takes to locate a particular file, starting with
the drive letter and then specifying the folders if any and then the file name.
PbPrY Also known as YPbPr / YprPb. A method for defining colour in analogue formats. PbPrY
is the analogue counterpart to YCbCr (component digital video). See YPbPr / YPrPb.
PrPbY See PbPrY.
PC Personal Computer. Typically used to refer to IBM and IBM clone personal computers
based on the x86 architecture.
PCI Peripheral Component Interconnect. A local bus standard with associated expansion slot
allowing fast transfer of data with PCI-compliant expansion cards.
PCI-express A newer, much improved version of PCI.
PCMCIA Personal Computer Memory Card International Association; this is an association of
companies that has produced a common standard for PC card-based peripherals and the
associated expansion slot. Primarily found on laptops, PDAs and other portable
computers.
PCT / PICT PiCTure. The Macintosh vector graphic file format. When converted for PC, the files have
the .pct file extension.
PDA, palmtop Personal Digital Assistant. Also known as a hand-held computer. A very small personal
computer.
PDF Portable Document Format. A document file format developed by Adobe that renders a
reliable reproduction of the original paper document or computer file. Fonts may be
embedded into the file such that they are not required on the computer on which the
document is to be displayed. ‘Reader’ programs that can display PDF files are produced
by Adobe. Versions are available for a range of computer systems and they are free to
download from the Adobe web site.
Peer Any computer operating on the same protocol level on a network.
Peripheral An external device that can be connected to a computer, eg, printer, scanner etc.
PictBridge PictBridge is the industry standard from the Camera & Imaging Products Association
(CIPA) for direct printing, that allows you to print images without a computer by directly
connecting digital cameras, etc, to a printer regardless of the device brand or model.
Pixel Picture Element. The smallest addressable unit on a display or image. In colour systems,
each pixel contains red, green and blue sub-pixels.
Platform The type of computer or operating system.
Plug and play
(PnP)
The ability for a device to be used simply by plugging in, without the need to install a
driver manually.
Plugin An auxiliary program that works with a software package to enhance its capability.
PNG Portable Network Graphics. An improved version of the bitmap graphics format that uses
the .png file extension.