There is a very large vocabulary of technical and descriptive terms that go with home theater. We've included the terms that you are most likely to encounter. If you are very technically involved you may find some of the more technical terms omitted from our list.

1080i - 1080 interlaced. One of the two formats used in high-definition television (HDTV). It indicates the number of vertical pixels displayed. The format is 1,080 pixels by 1,920 pixels which represents the 16:9 aspect ratio of widescreen television. Interlaced pictures are drawn in two passes instead of one pass from top to bottom.

16:9 Aspect Ratio - Pronounced 16 by 9. Widescreen format that corresponds to high definition broadcasts and closely corresponds to the widescreen format movies on DVD.

3-2 Pulldown - A method to convert movie film, which runs at 24 frames per second (fps), to video which runs at 30 fps. It is more accurate to call it 2-3 pull down because of the method of inserting material to reformat the film.

4:3 Aspect Ratio - Pronounced 4 by 3. The standard, almost square screen of NTSC style televisions.

480i - 480 interlaced. Standard-definition digital television. This provides a clearer picture than is achieved with regular off-the-air (OTA) or analog cable broadcasts. This is the resolution a DVD will display on an NTSC analog television.

480p - 480 progressive. Standard-definition digital television. This provides a clearer picture than is achieved with regular off-the-air (OTA) or analog cable broadcasts. This is the native resolution for DVD's and will be displayed with a properly connected progressive scan DVD player to an ED or HD television. This format is also known as Enhanced-Definition (EDTV).

CableCard - Roughly the size of a double thick credit card, this device is designed to take the place of your cable TV set-top-box. The TV must be equipped with a CableCard slot to work. At this time, CableCards (which are provided to you through your cable company) do not support all the services your provider may offer such as "on demand" movies or interactive menus.

DLP - Digital light processing. A rear projection television based upon technology that uses a chip with hundreds of thousands of microscopic moving mirrors. Each mirror corresponds to a single pixel on the screen. Light is reflected through an RGB color wheel to create the required colors. More expensive models use three separate mirror devices, one for each color, instead of using a color wheel.

DVR - Digital Video Recorder. aka PVR or Personal Video Recorder. Similar to a VCR although with much greater capabilities. A DVR records to an internal hard disk drive. It can record and play back a different recording simultaneously. With it you can pause live television and in some cases record more than one show simultaneously. It allows for easy set-up to record a program one time or on an ongoing basis. While once a subscription product available from a small number of companies like Tivo or Replay, many cable companies and satellite systems are now offering the service.

HDMI - High-Definition Multimedia Interface. High bandwidth connection allowing uncompressed transmission of digital video and audio. Successor to DVI; compatible with DVI with the use of an adapter.

HD-DVD - High-Definition Digital Video Disc. DVD format that supports high-definition 1080 lines compared to present DVD of 480p. Leading competitor to Blu-Ray in the battle to establish the new standard.

HDTV - High-definition television. A subset of the DTV standard called ATSC. The new broadcasting standard replaces the old NTSC analog standard. The HDTV signal is digital, supports vertical resolution up to 1080 lines and a widescreen aspect ratio of 16:9.

LCD - Liquid Crystal Display. A panel consisting of two transparent polarizing panels with a liquid crystal material sandwiched between. When voltage is applied, individual crystals turn dark. Behind the panels is a light source which flows through clear crystals and is blocked by dark crystals. The pattern of off and on crystals creates the image.

Letterbox - Because some images, such as wide-screen movies, do not fill a TV screen, black bars are placed above and below the image to fill the unused space. This allows to movie to be shown in its native aspect rather than being adjusted to fit the screen. When bars are placed to the left and right sides of an image it is called windowbox.

Plasma - A technology used for the creation of one of the two types of thin panel displays. Plasma displays have two glass panels with roughly one million pixels sandwiched between. Each pixel has three cells, one red, one green and one blue. Each cell is filled with a gas and when current is applied the gas emits UV rays which stimulate the phosphors to glow. The process is similar to the way a fluorescent light glows.

Progressive Scan - An image that is painted line by line in a continuous fashion. Compare to interlace scan which paints every other line, requiring two scans to create a complete image.

Throw Distance - Video projectors typically are rated for minimum and maximum throw distances. The minimum distance is the closest the projector can be placed to the screen while maintaining proper focus. The maximum distance is typically a recommended distance based upon image brightness.

Throw Ratio - For video projectors this ratio is the throw distance divided by the width of the projected image. A fixed throw projector can only change the image size by moving the projector closer or farther from the screen. Video projectors with a zoom feature can adjust the image size by zooming in or out, while leaving the projector itself unmoved.

THX - A playback standard developed by Lucasfilm. It is not a recording technology as many mistakenly believe. It is a rigorous set of standards for equipment used in the playback at theaters and more recently in homes.

Universal Remote Control - A remote control that is able to control several different audio and video components. The manufacturer provides a list of codes that the user must program into the remote for their own specific brands and models of equipment.