5.1 An arrangement of five speakers used to create surround sound (preferable to the inferior 2.1 system).
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 Digital UK to see when your area switches.
Aspect ratio Shape of the screen (width:height). The vast majority of TVs are now widescreen 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 (left) and optical (right)
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.
DVD disc types (RW, RAM etc) Not all DVDs 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 weeks 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.
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 (to Blu-ray) high definition DVD format developed by Toshiba, which the manufacturer has now abandoned.
HDMI is the best way of connecting your HD TV
HDMI Some players also feature an HDMI output. This is a high definition video socket, which many manufacturers claim will enhance standard-definition DVD pictures when connected to a HD ready TV.
We tried it out with a Best Buy Sony LCD TV the results were mixed. The Sony DVP-NS76H Best Buy is the only model to really show any big improvement in picture quality. However, a lot may depend on the TV its plugged into.
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. Sky and Freesat (satellite) and Virgin (cable) broadcast HDTV channels.
To watch you need a subscription to either one of these services and an 'HD ready' TV. However, not everything on the dedicated HD channels is actually recorded in HD. More programmes are being recorded in HD all the time but content can be a bit thin on the ground.
IDTV Integrated digital TVs have Freeview tuners built in so you can receive digital TV and radio channels free.