Analogue Tuner This picks up the old-style analogue TV signals for terrestrial channels. These signals will be switched off from later this year until 2012. Go to www.freeview.co.uk/ switchover to see when your area switches.
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. The aspect ratio of digital TV is suited to widescreen TVs
Audio description This is an additional narration for visually-impaired people that describes significant visual information, such as body language and scenery. The service is available on Sky 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.
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.
Coaxial If you use surround sound, be careful. There are two types of digital connections - coaxial (wire) and optical (fibre optic). Make sure your surround sound system input matches the input on your TV and your DVD recorder.
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.
DTS Digital theatre system: a surround-sound standard that is used in home cinema systems.
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. Called Blue Ray
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.
All DVD players will play pre-recorded DVDs (those you rent or buy).
DVI input This is the standard digital input used for high definition video. Unlike HDMI it cannot carry audio signals.
EPG Electronic programme guides display schedules of the week’s digital programmes on screen.
Flat panel display The general term that is used for LCD and plasma technologies.
Freeview A service that provides digital television through an aerial. The service is 'free to air' which means that viewers do not need to subscribe to watch the broadcasts. Although most early viewers had to by a set top box to watch Freeview, digital tuners are increasingly appearing in flat panel televisions.
Freesat HD A service that provides digital television through a dish . The service is 'free to air' which means that viewers do not need to subscribe to watch the broadcasts. Freeview channels are available including HD Channels
HDD Hard Disk Drive. Familiar to computer users, these devices are now appearing in PVRs and some DVD recorders as convenient and flexible way of recording TV programmes. The larger the hard-disk size the more recordings you can store so an 80Gb HDD will give you around 40 hours of recording time. Typically a PVR will give you 40 or 80 hours of recording time.
HD compatible HD-compatible TVs have a lower screen resolution than HD ready TVs but they do have the right sockets to connect to a HD source.
HD DVD A rival high definition DVD format developed by Toshiba. Although it has less capacity than the Sony Blu-Ray rival, HD-DVD players are generally cheaper. HDMI is the best way of connecting your HD TV. (HD -DVD Players are now no longer produced)
HDMI Some players also feature an HDMI output. This is a high definition video socket, which many manufacturers claim will enhance standard DVD pictures when connected to a HD ready TV.
HD ready 'HD ready' is a labelling scheme introduced by the TV manufacturers' organisation, the European Industry Association for Information Systems (EICTA). The label means the TV has the minimum screen resolution (at least 1280x720) and digital sockets (HDMI or DVI) to receive and display an HD picture.
High-definition television (HDTV) HDTV is a new system that transmits a TV signal with roughly twice the standard picture resolution as normal standard definition telly. Both Sky (satellite) and Telewest (cable) operate HDTV channels. And now a new satellite service called Freesat is available providing HD and freeview channels with no subscription
IDTV Integrated digital TVs have Freeview tuners built in so you can receive digital TV and radio channels free.
LCD TV Type of flat panel where light shines on to liquid crystal cells on screen that let varying amounts of colour through to create a picture.
Multiplex A group of digital TV channels grouped together for broadcast. A multiplex can also carry radio and interactive TV content.
Native resolution The number of pixels on screen (width x height).
Optical output If you use surround sound, be careful. There are two types of connection, coaxial and optical. If you already have a surround sound system, make sure you buy a DVD recorder with the same connections.
Phono sockets Dedicated red and white sockets to allow you to connect your TV to a stereo amplifier - useful if its built-in speakers aren't that good.
Picture enhancement features Be wary of these digital effects, designed to make pictures sharper and movement smoother. Our tests show they sometimes degrade picture quality.
Picture in picture (PiP) Picture-in-picture displays a small image of another channel or DVD in the corner of the screen while you watch the main image.
Plasma TV Type of flat panel where tiny gas cells emit ultraviolet light that strikes red, green and blue spots on screen to make a picture. Usually the larger size flat panel TVs 37” and above
PVR A Programmable Video Recorder is a digital television hard-disk recorder. You programme it using an on-screen display of TV listings which makes it much easier to use than a video recorder.
Rear projection TV Reds, blues and greens of TV images are projected on to a mirror and then reflected onto the screen.
Resume Resume means the player will start the disc where you stopped it (instead of at the beginning each time). Models with multi-disc resume remember where to start playing the disc even after you’ve removed it and reinserted it.
RF Input Connects to your aerial and allows the broadcast signal to be received by your tuner.
RGB This is a high standard analogue video signal that splits the red, green and blue components to give the best picture. The best Scart sockets carry an RGB signal.
S-video input If you're short of Scart inputs s-video can provide an alternative. S-Video signals are split into colour and brightness but are slightly inferior to Scart RGB. It’s usually used to plug other AV equipment, such as camcorders and games consoles, directly into your TV.
Scart All-purpose 21 pin socket to connect equipment such as DVD players and VCRs to your TV. Most TVs now come with at least two Scart sockets. If you need more, you can buy a Scart switching box for £10 or so to expand your TV's capacity. For the best picture, look for Scarts that support the high-standard RGB signal. This splits the video signal into its red, blue and green components to give an improved picture.
Scart sockets Two Scart sockets give you more versatility. The first connects to the TV and carries the higher quality RGB signal and widescreen switching information that tells your telly when to switch between conventional and widescreen formats. The second Scart socket links to your recorder (video or DVD) – ideally this should carry RGB too, though often it doesn’t.
S/P-DIF Sony/Philips digital interface format: used to carry digital audio by surround sound systems. There are two types: optical (sometimes called TOSLINK) and coaxial.
Surround sound All DVD players can be connected to external surround-sound decoders (Dolby Digital 5.1 etc), amplifiers and speakers so you can experience ‘cinema-like’ surround sound. Virtually all DVDs have the surround sound tracks on them.
Some players have a built-in Dolby Digital surround-sound decoder, but you’ll still need additional surround sound amplifiers and speakers to get the home cinema experience, so there’s really any advantage over using an external decoder.
However, on occasion, a DVD-Audio surround sound decoder is also built-into the player. These are included so that players which can play back audio discs recorded in the higher-quality DVD-Audio format can also decode the surround sound tracks, which often come with these discs. This makes more sense but again you’ll still need external amplifiers and speakers to hear this surround-sound.
UHF modulator If your TV doesn't have a Scart input (Scart isn't usually available on older models), you'll need a set-top box with a UHF modulator, which connects to the TV's aerial socket.
UHF loopthrough None of the Freeview set-top boxes let you watch one digital programme while recording another on your VCR. However, if you opt for a box with a "UHF loopthrough", you can record a digital programme while watching an ordinary analogue channel (or vice versa), with minimal disruption to your TV and VCR connections.
VGA A VGA input lets you connect your PC - effectively turning your TV into a PC monitor. Digital DVI sockets provide an alternative but in our tests VGA looked better on the screen. DVI can over enhance the picture, making it too sharp.
Video on demand (VOD) VOD services let you to either 'stream' TV, allowing viewing in real time, or 'download' to a set-top box before viewing starts.
Video input If you're short of Scart inputs composite video can provide an alternative. Composite video (usually a yellow phono socket) is the lowest quality video connection. It’s usually used to plug other AV equipment, such as camcorders and games consoles, directly into your TV.