Glossary Of Terms
The relationship between the width and height of a television screen that defines its shape. Standard TV sets have an aspect ratio of 4:3, i.e. four units wide by three units high. If the screen is 24 inches wide it will be 18 inches high. Widescreen TVs have an aspect ratio of 16:9 which gives a ‘letterbox’ shape like a cinema screen.
Particularly useful for visually impaired viewers, a spoken commentary describes what happens on screen between dialogue, including action sequences, facial expressions, scenery, and so on.
The range of frequencies used for transmitting a signal. Digital broadcasting takes up less bandwidth than analogue which allows extra channels, services etc. to be broadcast.
A system or circuit that carries signals over a wide range of frequencies or bandwidth. The wider the bandwidth, the more information that can be carried. Broadband internet gives you a high-speed connection suitable for downloading audio, video etc.
Cathode Ray Tube – the standard type of deep bodied TV set.
Digital audio broadcasting: the transmission system now used for digital radio.
Digital Cable: digital TV received via cable connection.
A device that unscrambles digital signals and turns them back into sound and pictures. A decoder can be a set-top box, or be built into a TV set or PVR.
A separate digital set-top box.
The new way to broadcast TV and radio. Digital signal codes the pictures and sound being broadcast into computerised data. The signal is then turned back into pictures and sound by a decoder.
Digital Light Processing: used in rear-projection flat panel TV screens.
Digital on-screen graphic: a channel identification logo, for example, usually seen in the left-hand corner of the TV screen.
Digital Satellite: digital TV received via satellite dish.
Digital Terrestrial Television: digital TV received via standard aerial.
Digital Video Broadcasting, the European standard digital TV technology.
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 incompatible formats.
Digital visual interface: digital connection for high-quality video, suitable for HD TV.
Digital video recorder: known more commonly as PVR (personal video recorder), this records TV programmes digitally on to a hard disk (like saving information on a computer
Electronic programme guide: provides on-screen listings of what’s on, often for a number of days or weeks ahead, depending on digital service you have.
Free to air (FTA)
A subscription free programme service.
The company that now supplies the UK’s free digital terrestrial TV service.
High-definition television: has four times as many pixels as standard-definition TV. This gives a clearer, sharper image with much more detail. HD TV also has better quality sound.
Integrated digital television: TV set with a built-in digital TV receiver that can receive Freeview channels without a separate set-top box.
Features added to TV programmes that provide extra information, allow you to join in with things like quizzes or make choices on what you view.
Liquid crystal display: the picture displayed on a flat-panel screen. LCD is particularly suitable for large TV screens and good for HD TV.
Personal digital recorder. See PVR.
Short for picture element: a single dot on TV screen (or computer screen or digital photo). Thousands of pixels make up a picture and the more pixels the better the picture. High-definition TV has up to four times as many pixels as standard-definition TV.
The picture is displayed on flat-panel screen, using gases behind the glass. Plasma is particularly suitable for large screens and good for HD TV.
A system for delivering TV and radio services in broadcasting. Digital TV, for example, is now delivered mainly on terrestrial, satellite and cable platforms.
Pay-per-view: an individual programme or series that you pay money to receive.
Personal video recorder (also known as a DVR [digital video recorder] or PDR [personal digital recorder]): Records TV programmes onto a hard disk, like saving information on a computer, instead of onto video tape or DVD. It has a built in electronic programme guide (EPG) and allows you to pause and ‘rewind’ a programme while you are still watching it.
Radio frequency: an RF connector is used to feed a TV signal from an aerial to TV, video recorder, etc.
The type of connector most commonly used to connect TVs, video recorders, DVD players, set-top boxes.
Also known as a ‘viewing card’: this plastic card is inserted into the slot in a set top box or TV set that decodes signals and allows you to received digital services such as Sky or Top Up TV.
Set-top box unit.
TV broadcast and received via an aerial.
Video on demand: service that allows you to receive and watch selected TV programmes when you want to, rather than when they are broadcast.
TV picture that gives a ‘letterbox’ shape like that of cinema screen, with an aspect ratio of 16:9.