Technical information

© CLEAPSS 2005 1645 ICT in the Science Department
Breakpoint A point that can be set in a computer program where execution is halted when the
program is run in order that the values of data and the programs operation may be
inspected.
Broadband In simple terms, a fast Internet connection. More accurately, a communications system in
which the cable may carry multiple transmissions at any particular time.
Browser A Web browser, often just called a ‘browser’, is the program used to access the World
Wide Web. It interprets the HTML code that web pages are written in. Common browsers
are Microsoft Internet Explorer and Netscape. The term may also be applied to any
program that permits ‘browsing’ of files or pictures etc.
Buffer A reserved segment of memory used to hold data while it is being transferred between
two locations or devices.
Bug An error in a computer program or a hardware fault in a computer system.
Buggy A wheeled model, often completely steerable using two reversible motors. Alternatively,
refers to software that contains bugs.
Burn To write data to a source, eg, writing data to a compact disc. Usually this is a once-only,
irreversible procedure.
Bus An internal pathway that serves as a common connection for a group of related devices or
components.
Byte A pattern of eight bits. A byte can represent a single character (digit, letter or punctuation
mark).
Cache Storage used to hold a duplicate of frequently-used data in order to provide fast access.
CAD / CAM Computer-Aided Design / Computer-Aided Manufacture.
Camcorder CAMera / reCORDER. A camera designed to capture and record moving images.
Candela (cd) A unit of measurement of brightness. The brightness of computer monitors is typically
specified in candelas per square meter (cd/m
2
). An ordinary wax candle generates
approximately one candela.
Capture To transfer received data into a file; to import data, eg, video or pictures, to a computer
file from a peripheral device, eg, a video recorder.
Capture card See Video-capture card.
Card A printed circuit board carrying an electronic circuit that is usually plugged into a computer
expansion slot in order to give an added facility.
Cat 5 cable Category 5 cable. Cable used for Ethernet network connections.
CCD Charge-Coupled Device: a microchip with an array of sensors. Each sensor produces one
pixel of information. All types of digital camera use CCD or CMOS sensors to detect
images.
CD Compact Disc. A portable disc storage medium that can contain programs or data files for
use on a computer. Can store many times more data than a floppy disc.
Check bit One of a set of bits added to a data transmission that permits the recipient the ability to
check that the information was not corrupted during transmission.
Checksum A value derived from a mathematical operation involving all the bytes in a file or data
transmission. The recipient may then check that value against the value after trans-
mission. If the values do not match, then an error has occurred.
Chip Short for microchip.
Chroma See Chrominance.
Chrominance The signal, or portion of a composite signal, that carries the colour information.
A
lternatively, the colour of a pixel. Represented by the letter ‘C’, chrominance is made up
of saturation and hue values, but is separate from the luminance value.
Clicking Pushing a button on a mouse to initiate some action having first moved the mouse to
guide a pointer to the desired position on the screen.
Client Typically used to refer to a networked or Internet-connected computer that utilises serv-
ices provided by another computer (a server).