Jargon Buster

Analogue

The previous way of broadcasting television and radio. An analogue signal directly represents the pictures and sound, whereas a digital signal codes the pictures and sound into 'computerised' data.

Aspect ratio

The relationship between the width and height of a television screen that defines its shape. A standard TV set has an aspect ratio of 4:3, i.e. four units wide by three units high. So, for example, if the screen is 24 inches wide it will be 18 inches high. A widescreen set has an aspect ratio of 16:9, giving a 'letterbox' shape like that of a cinema screen. The programmes on most of the major TV channels are now in 16:9 format.

Audio description

A spoken commentary that describes what is happening on screen, particularly useful for visually impaired viewers. The commentary fits in between dialogue and describes action sequences, facial expressions, costume, scenery and so on.

More information: Digital TV – audio description.

Bandwidth

The range of frequencies used for transmitting a signal. Digital broadcasting takes up much less bandwidth than analogue.

Broadband

Refers to a system or circuit that can carry signals over a wide range of frequencies or bandwidth. The wider the bandwidth, the more information that can be carried. For example, broadband internet gives you a high-speed connection suitable for downloading video and audio, etc.

CRT

Cathode ray tube, as in the standard type of large-bodied TV set.

DAB

Digital audio broadcasting: the transmission system used for digital radio.

DCAB, D-CAB

Digital cable: digital TV received via a cable connection.

Decoder

A device that unscrambles digital signals and turns them back into sound and pictures. It may come as a set-top box, or be built into a TV set or PVR.

Digibox

Informal way of referring to a digital set-top box.

Digital

The new way of broadcasting television and radio. A digital signal codes the pictures and sounds into 'computerised' data. The signal then has to be turned back into pictures and sounds by a decoder.

Digital can also refer to the way radio station frequencies are displayed as numbers on an FM/AM radio. This is not the same as DAB digital radio.

DLP

Digital light processing: a technology used in rear-projection flat-panel TV screens.

DOG

Digital on-screen graphic: a channel identification logo, usually seen in the top left-hand corner of the TV screen.

DSat, D-SAT

Digital satellite: digital TV received via a satellite dish.

DTT

Digital terrestrial television: digital TV received via a standard aerial.

DVB

Digital Video Broadcasting, the European standard for digital TV technology.

DVD

Digital versatile disc, or digital video disc: DVDs give better picture and sound quality than video cassettes, and can store more than CDs. They can be used in DVD players and recorders and also in computers, though there are different, often incompatible formats.

DVI

Digital visual interface: a digital connection for high-quality video, suitable for HD TV.

DVR

Digital video recorder: more often known as a PVR (personal video recorder), this records TV programmes digitally on to a hard disk (like saving information on a computer).

Ensemble

A digital radio term for a single frequency that contains a number of radio channels. See also Multiplex.

EPG

Electronic programme guide: on-screen listings of what's on TV now, and often for a number of days or weeks ahead, depending on which digital service you have.

Free to air (FTA)

A programme or service that you don't need to pay a subscription to receive.

Freesat from Sky

Free satellite TV service, where you pay for the equipment but don't pay a subscription to receive free-to-air channels.

Freeview

Company that supplies the UK's free digital terrestrial TV service.

HDMI

High-definition multimedia interface: a digital connection using a single cable for high-quality video and audio.

HD TV

High-definition television: it has up to four times as many pixels (dots on the screen) as standard-definition TV. The pixels make up the lines on a screen: standard screens have 625 lines, while HD screens have 720 or 1080 lines. This gives a clearer, sharper picture with much more detail. HD TV also has better quality sound.

IDTV

Integrated digital television: a TV set with a built-in digital TV receiver that can get Freeview without a separate set-top box.

Interactive TV

Features added to TV programmes that let you get extra information, join in with things such as quizzes, or make choices about what to view. You access interactive features via the red button on the remote control.

iPlayer

New service which lets you access BBC television programmes via your PC.

LCD

Liquid crystal display: a technology that displays a picture on a flat-panel screen. It is particularly suitable for large-size TV screens and is good for HD TV.

Multiplex (abbreviated to MUX)

A single broadcast frequency that contains a number of different TV or radio channels. For example, six multiplexes carry all the TV channels and radio networks on Freeview and Top Up TV Anytime.

PDR

Personal digital recorder. See PVR.

Pixel

Short for picture element: a single dot on a TV screen (or computer screen or digital photo). Thousands of pixels make up the picture, and the more pixels the better the picture. High-definition TV has up to four times as many pixels as standard-definition TV.

Plasma

A technology that displays a TV picture on a flat-panel screen by using gases behind the glass. It is particularly suitable for large-size screens and is good for HD TV.

Platform

In broadcasting, a system for delivering TV and radio services. For example, digital TV is delivered mainly on terrestrial, satellite and cable platforms.

PPV

Pay-per-view: an individual programme or series that you pay to receive.

PVR

Personal video recorder; also known as a DVR (digital video recorder) or PDR (personal digital recorder). It records TV programmes digitally on a hard disk (like saving information on a computer), instead of on video tape or DVD. It has an electronic programme guide (EPG) built in, and allows you to pause and 'rewind' a programme while you are watching it.

RF

Radio frequency: an RF connector is used to feed a TV signal from an aerial to a TV, video recorder, etc.

SCART

The type of connector most commonly used to connect TVs, video recorders, DVD players and set-top boxes.

Smart card

Also called a viewing card: a plastic card inserted into a slot in a set-top box or TV that decodes signals and allows you to receive digital services such as Sky and Top Up TV Anytime.

STB

Set-top box.

Terrestrial

TV that is broadcast and received via an aerial. See also DTT.

VOD

Video on demand: a service that allows you to receive and watch selected TV programmes when you want, rather than when they are broadcast.

Widescreen

TV pictures with an aspect ratio of 16:9 that gives a 'letterbox' shape like that of a cinema screen. The programmes on most of the major TV channels are now in widescreen format.