Digital Television Dictionary

4 X 3
Refers to the TV screen’s width as compared to its height. This is a traditional TV aspect ratio.

16 X 9
This is the aspect ratio for a "widescreen" TV format, which more closely resembles a movie screen than a traditional TV.

Analog Spectrum
A traditional, less-efficient and lower quality system that uses radio frequency (RF) waves to transmit and display pictures and sound.

ATSC Tuner
Often called an ATSC receiver or HDTV tuner, allows reception of digital television (DTV) signals broadcast over-the-air by TV stations. May be integrated into a television, VCR, digital video recorder, or set-top box.

Blue-ray
An optical disc that can record and play high-definition video. Typically cost more than an HD-DVD player.

Broadcast Spectrum
The entire range of frequencies used for radio and television transmission.

Broadcasting
Using radio waves to distribute radio or TV programs which are available for reception by the general public.

Department of Commerce (DOC)
Department whose responsibility is to "foster, serve, and promote the Nation's economic development and technological advancement".

Digital
Describes a new, more efficient method of storing, processing and transmitting information through the use of computer code.

Digital Cable Ready (DCR)
A "plug-and-play" DTV for digital cable customers that plugs directly into the cable jack and does not require a separate set-top box.

Digital Television (DTV)
The umbrella term used for the new broadcasting system that uses computer code to transmit pictures and sounds. DTV includes all types of digital broadcasting, including High and Standard Definition television, datacasting and multicasting.

Digital-to-Analog Converter Box
A stand-alone device that receives and converts digital signals into a format for display on an analog television receiver.

High-Definition Television (HDTV)
One type of digital television signal that is broadcast at a higher resolution than the others, providing a higher-quality picture in terms of color, motion and clarity.

HD-DVD
A high-definition DVD that can record and play high-definition video. Offers less memory than Blu-ray; typically cost less than Blu-ray.

Household
All of the people who occupy a housing unit. A housing unit is a house, an apartment, a mobile home, a group of rooms, or a single room occupied as separate living quarters. Separate living quarters are those in which the occupants live separately from any other people in the building and that have direct access from the outside of the building or through a common hall.

LCD TV
(Liquid Crystal Display) Flat-panel TV that ranges from 15 to 65 inches. Thinner and lighter than plasmas, consumes less power and comes in smaller sizes than plasma TV. Often more expensive than plasma TV. Light isn't created by the liquid crystals; a light source (bulb) behind the panel shines light through the display. Used in flat-panel, rear-projection, and front-projection TVs.

Letterboxed video
On a TV screen with standard aspect ratio (4:3), letterboxed videos appear with horizontal black bars above and below the image. This is a method for displaying the entire picture, as seen in a movie theater.

Multicasting
The ability to transmit multiple standard-definition programs at the same time using a single digital broadcast channel.

Nation Telecommunications and Information Administration (NTIA)
The President's principal adviser on telecommunications and information policy issues.

NTSC Tuner
A device built-in to a TV that allows reception of analog broadcasting.

Over-the-air
Refers to the transmission and reception of information in a wireless communication system.

Pixel
A pixel is the smallest picture element in a TV image. The more pixels in an image, the greater the resolution.

Plasma TV
A flat-panel TV that ranges from 42 to 102 inches. Because it offers wider viewing angles, is often preferred for displaying fast action, such as sports.

Rabbit ears
A V-shaped set-top antenna that is adjustable in length and angle.

Rear-projection TV
Displays a TV image by projecting images on the back of a screen. Typically referred to as "big-screen" TVs.

Resolution
Amount of detail that can be seen in a broadcast image (amount of lines and dots (pixels) that make up an image). Typically, the higher the number of lines or pixels, the sharper and more detailed the picture will be.

Rooftop antenna
An antenna mounted on the roof of a structure.

Set-top box
A stand-alone device that connects to a television and an external source of signal, turning the signal into content which is then displayed on the television screen.

Simulcast
The broadcasting of the same program on two different channels or frequencies. Until the DTV transition deadline, much of broadcast networks' DTV content must be simulcast with regular TV.

Standard Definition TV (SDTV)
The basic digital television format closest in quality to traditional analog TV. Transmission of SDTV may be in either the traditional (4:3) or wide-screen (16:9) format.

TiVo
(Pronounced tee-voh) A brand of digital video recorder (DVR) in the United States and Canada that captures television programming to hard disk storage for later viewing ("time shifting"). Also provides an electronic television programming schedule, and provides recording options based on that schedule.

Widescreen
Widescreen generally refers to an aspect ratio of 16:9, which is the optimum viewing ratio for DTV and HDTV broadcasts. Traditional TV sets have an aspect ratio of 4:3.