A - E
720p Lowest quality of the HDTV formats.
1080i Good quality HDTV format used to broadcast HDTV in the UK.
1080p Best quality form of hi-def video. Due to the massive amount of data it requires, it can't be used to broadcast HDTV. Not all HD-ready TVs accept 1080p signals.
Amplifier TV or Radio Signal amplifier/booster.
Antenna Term for an aerial used in Europe & U.S.
Analogue tuner This picks up the old-style analogue TV signals for terrestrial channels. The digital switchover has begun and these signals will be switched off.
Aspect ratio Shape of the screen (width: height). The vast majority of TVs are now wide-screen with an aspect ratio of 16:9. Older TVs and some portables have an aspect ratio of 4:3. Digital TV is broadcast in a widescreen format.
Attenuator Reduces Signal Strength.
Audio description This is an additional narration for visually-impaired people that describe significant visual information, such as body language and scenery. The service is available on Sky, Freesat and Freeview. Only a handful of the latest TVs can decode audio description on Freeview.
Auto-format switching it's a good idea to choose a widescreen TV that automatically alters how different broadcasts are displayed – for example, showing standard (4:3) broadcasts with black bands on either side so the images aren't stretched out of proportion. Most widescreen TVs will do this.
Auto power-off If you leave your equipment switched on when not in use, this handy energy-saving feature will switch it into standby after a given period of idleness.
Backwards compatible Product that can use earlier iterations of software or video formats (like DVDs).
Black level control This adjusts the pictures' black level. This is useful for watching movies with particularly dark sequences, like the Matrix. LCD TV pictures can often look a bit washed out so any boost from the DVD can be especially helpful.
Blu-ray A new high definition DVD format developed by Sony. Aimed mainly at serving the new high definition TV market with cinema quality movies, a Blu Ray disc can hold nine hours of high-definition (HD) video and around 23 hours of standard-definition (SD) video on a 50 GB disc.
Bookmarking Models with bookmarking let you mark favourite scenes or places in a disc so you can quickly find them again. More sophisticated DVD players let you bookmark several discs, and will 'remember' your bookmarks even when the disc is removed.
Booster TV or Radio Signal amplifier/booster.
CAI Confederation of Aerial Industries - represents manufacturers, installers & other interested parties.
CATV Community Aerial TV - covering a set neighborhood/Town/City/County.
Chimney lashing kit Used to secure an aerial to a chimney.
Coax coupler Used to join together 2 Coax Plugs.
Coax plug Terminates coaxial cable for insertion to TV etc via a coax plug.
Coaxial cable Aerial lead to appliance.
Colour gamut The range of colours detectable by human eyes a TV can display.
Combiner Combines two or more aerial leads into one single aerial (coaxial) lead.
Common Interface Slot for a CAM. EU regulations require every IDTV to have at least one common interface.
Component This is a high quality video input made up of three sockets coloured red, green and blue. Also known as YPbPr, it splits the video signal into three separate parts for an improved picture. However, component connections are still not widely used on AV equipment and unlike Scart sockets they do not carry the widescreen switching signal.
Composite input (see video input).
Contrast ratio How dark and bright the picture on a flat-panel TV will go.
CRT Cathode ray tube – the technology behind traditional big-box TVs.
DAB Digital audio broadcast.
DAB Radio Stereo Digital Radio offering a wide range of channels, as an alternative to FM.
DAB aerial Enhances DAB reception.
Db Decibel - signal measurement.
Digital Aerial Aerial/Antenna capable of receiving the new digital signal, providing more channels and enhanced services for the UK.
Digital Tick The digital tick appears on products and services that are designed to work before, during and after switchover. If you need to upgrade your aerial look for a Registered Digital Installer (RDI). (See RDI)
Diplexer Combines two or more aerial leads into one single aerial (coaxial) lead.
Dipole This element connects to the aerial downlead, receiving signals from the director and reflector elements.
Director element Forward of the dipole, these are a series of tuned elements.
Dish pack The satellite dish or external part of a sky installation.
Distribution amplifier Used to amplify the aerial signal when sending signals to two or more TV's or Radios, this is the signal booster (see Amplifier).
Downlead This is the cable which connects the aerial or dish to TV, radio or set top box.
DTT Digital Terrestrial TV.
Dolby and DTS Sound formats.
DTS Digital theatre system: a surround-sound standard that is used in home cinema systems.
DSP Digital signal processing. Types of sound modes with names such as music and movies.
Dual-layer DVD (DL DVD) DVDs with nearly double the capacity of normal DVD-R discs. Double Layer is its DVD+R counterpart.
DV (Digital Video) Format found mostly on digital camcorders. Many DVD recorders have DV-inputs (aka i.Link) and a handful also have DV-outputs.
DVD The DVD has become the standard method of renting and playing films over the past few years replacing video cassettes. The DVD itself is about to be replaced by the next generation of 'high-definition' DVDs.
DVD disc types (RW, RAM etc) Not all DVD discs are the same. There are several different recording formats – DVD-R, DVD+R, DVD-RW, DVD+RW and DVD Ram – each with slightly different features and capabilities. Check with sales staff to ensure your discs can be played on your new device.
DVD+R Rival format to DVD-RW. Recordings will play on most DVD decks.
DVD-Audio High-quality audio format. Similar to SACD in quality items, but can also have video content on the discs.
DVD-R A recordable DVD format which makes a permanent copy onto a disk that cannot be re-recorded.
DVD-RAM Highly versatile recordable DVD format that offers simultaneous recording and playback, and non-linear editing.
DVD-RW Recordable version of DVD-R. Offers two recording modes-Video Mode and Video Recording Mode. Video mode allows basic editing changes, but universal playback compatibility. Video Recording Mode gives more editing options, but discs can only be played back in compatible DVD players.
D-VHS Hi-def video tape format. Not available commercially in the UK.
DVI (Digital Video Interface) input This is the standard digital input used for high definition video. Unlike HDMI it cannot carry audio signals. Digital socket used to transmit HDTV signals. DVI sockets must be HDCP-compatible to display HDTV.
EPG Electronic programme guides display schedules of the week's digital programmes on screen.
