Technical information

© CLEAPSS 2005 1647 ICT in the Science Department
Data key See Memory card.
Datalogging The collection and recording of data over a period of time using a computer or similar
electronic device.
Data projector A projector that can project the images from a digital device onto a screen. Data
projectors may also be able to project images from analogue inputs.
DDI Device Driver Interface. See WIA.
Decoding To ‘unencode’ information that has been processed according to a code or rule.
Decompression Decompressing a compressed file to its full size.
Defrag To organise the arrangement of blocks of data on a disk into groups such that blocks
belonging to a particular file are all adjacent. This can speed up the rate at which such
files are accessed.
Desktop An area of a computer’s display used to keep items that are convenient for quick access
or are currently being worked on - intended for use as you would keep items on an actual
desk.
Dial-up
connection
A narrowband connection system for computers using the public telephone network to
connect to the Internet.
Digital Refers to something based on discrete values or digits (numbers) or their representation.
Digital8 The Digital8 standard uses the DV codec, but uses Video Hi8 tapes to record onto. The
Digital8 format was designed as a consumer format for transition from analogue to digital.
DIN Deutsches Institut für Normung. A multi-pin connector that conforms to a DIN standard.
Directory A catalogue of files and folder names stored on disk used to organise and group similar
items.
DirectX An API that provides routines for graphics and sound hardware.
Disc or disk A recording / storage medium used to hold computer programs and other digital inform-
ation.
Dithering A method used on a computer display to create the appearance of more shades or
colours than would otherwise be possible for that display.
DivX Digital Video eXpress. A movie file format.
DLP Digital
Light Processing. An alternative display technology to LCD used by some projectors.
Docking station A device into which a laptop can be plugged to provide extra connectors. This allows less-
mobile peripherals such as a printer to be permanently connected to the station while the
laptop may be easily removed and transported on its own.
Domain A territory of some description. A domain is a hierarchical system used to define an
Internet location or set of addressable computers.
Dongle This originally referred to a security device that must be plugged into a port on a computer
before the associated, protected computer program could be used. Today, the term is
often used to refer to any small device that attaches to a computer port (particularly those
that dangle from the port to which they are attached).
DOS Disc Operating System: that used by IBM-compatible computers, usually MS-DOS™.
Download The process of transferring a copy of data from a remote computer to your computer.
Drag and drop A technique used in GUI interfaces whereby the mouse pointer is placed over an icon or
similar, the mouse button is pressed and held whilst the mouse (and the icon) are moved
(‘dragged’) to the desired position. The mouse button is then released and the item is
‘dropped’ into its new location.
Driver A control program that enables a particular device to work with a computer.
DRM Digital Rights Management. Technologies designed to implement copyright restrictions on
digital materials.
DSE Display Screen Equipment. See VDU.
DTP DeskTop Publishing.