Glossary of HD Terms

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

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

5.1 Audio Format
This is a digital audio recording and playback system for home theater. It includes five channels (left, right, center, rear/surround left and right) plus a subwoofer channel. The major 5.1 channel standards are Dolby AC-3 and Philips Musicam.

Advanced Television Systems Committee
Also known as "ATSC," the committee responsible for digital television standards and development, as well as all 18 formats of DTV.

Analog TV
"Standard" television broadcasts analog TV. Analog signals vary continuously, representing fluctuations in color and brightness.

CableCARD
Digital cable customers may obtain this security card in order to view high-definition scrambled programming and premium services without a set-top box.

CRT (Cathode-Ray Tube)
A CRT ("picture tube") is a specialized vacuum tube in which images are created when an electron beam scans back and forth across the back side of a phosphor-coated screen. The regular "direct-view" TVs most people grew up watching have a single large picture tube, while CRT-based rear-projection and front-projection TVs use three CRTs: one each for the red, green, and blue primary colors. Each time the beam makes a pass across the screen, it lights up a horizontal line of phosphor dots on the inside of the glass tube. Images are created by rapidly drawing hundreds of these lines from the top to the bottom of the screen.

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 TV (DTV)
Television delivered and displayed using computer code (digital technology).

Enhanced Definition Television (EDTV)
EDTV refers to a complete product/system that receives ATSC terrestrial digital transmissions and decodes all ATSC table 3 video formats, has active vertical scanning lines of 480 progressive (480p) or higher and receives, reproduces, and/or outputs Dolby Digital audio.

EDTV Monitor
EDTV monitor refers to a monitor or display that has active vertical scanning lines of 480 progressive (480p) or higher.

EDTV Tuner
EDTV tuner refers to a RF receiver that receives ATSC terrestrial digital transmissions and decodes all ATSC table 3 video formats. It outputs the ATSC table 3 720p and 1080 i/p and 480p formats with minimum active vertical scanning lines of 480. Alternatively, the output can be a digital bit stream output capable of transporting 480p, except the ATSC table 3 480i format can be output at 480i. It also receives and reproduces, and/or outputs Dolby Digital audio.

High-Definition Television: (HDTV)
HDTV refers to a complete product/system that receives ATSC terrestrial digital transmissions and decodes all ATSC table 3 video formats, has active vertical scanning lines of 720 progressive (720p), 1080 interlaced (1080i) or higher. Is capable of displaying a 16:9 image and receives, reproduces, and/or outputs Dolby Digital audio.

HDTV Monitor
HDTV monitor refers to a monitor or display that has active vertical scanning lines of 720 progressive (720p), 1080 interlaced (1080i) or higher and is capable of displaying a 16:9 image. Manufacturers are required to disclose the number of vertical scanning lines in the 16:9 viewable area, which must be 540p, 810i or higher to meet the definition of HDTV.

HDTV-ready
Term used to describe TVs that can display digital high-definition TV formats when connected to a separate HDTV tuner. These TVs generally have built-in tuners for receiving regular NTSC broadcasts, but not digital. An HDTV-ready TV may also be referred to as an "HDTV monitor."

HDTV Tuner
HDTV tuner refers to a RF receiver with the following minimum performance attributes:

Integrated Tuner - An HDTV that has the tuner built into the set. It does not need a separate set-top box.
Receiver - Receives ATSC terrestrial digital transmissions and decodes all ATSC table 3 video formats.
Outputs - Outputs the ATSC Table 3 720p and 1080i/p formats in the form of HD with minimum active vertical scanning lines of 720p, 1080i or higher. Additionally, it may output HD for mats converted to other formats. The lower resolution ATSC Table 3 formats can be output at lower resolution levels. Alternatively, the output can be a digital bit stream with the full resolution of the broadcast signal.
Audio - Receives and reproduces, and/or outputs Dolby Digital audio.

Interlace Scan
A way to scan vertical lines onto a TV picture by scanning all the odd lines first, then filling in the even lines.

LCD (Liquid Crystal Display)
Liquid Crystal Display technology is one of the methods used to create flat-panel TVs. Light isn't created by the liquid crystals; a light source (bulb) behind the panel shines light through the display. The display consists of two polarizing transparent panels and a liquid crystal solution sandwiched in between. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal acts like a shutter, either allowing light to pass through or blocking the light. The pattern of transparent and dark crystals forms the image. LCD technology is used in flat-panel, rear-projection, and front-projection TVs.

LCoS (Liquid Crystal on Silicon)
A projection TV display technology that sandwiches a layer of liquid crystal between a cover glass and a highly reflective, mirror-like surface patterned with pixels that sit on top of a silicon chip. These layers form a microdisplay that can be used in rear-projection and front-projection TVs. Manufacturers use different names for their LCoS-based technologies. JVC uses D-ILA™ or HD-ILA™, while Sony uses SXRD™.

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.

National Television System Committee
The National Television System Committee, or NTSC, established our North American 525-line analog broadcast TV standard about 60 years ago. Although it is referred to as a "525-line" standard, we're only able to see 480 lines on a TV display. The ATSC digital broadcast standard will eventually replace NTSC.

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

Plasma
A display technology enabling thin, lightweight TVs that can be hung on the wall. Plasma TV pixels are composed of gas-filled cells where an electric current is applied to create the TV image.

Progressive Scan
TV images are displayed using vertical lines. Progressive scan is a way to produce the vertical lines of a TV picture by scanning all the lines consecutively (progressively).

Rear-projection TV
As the name defines, rear-projection TV’s display a TV image by projecting images on the back of a screen. These TV’s are typically referred to as "big-screen" TVs. Digital microdisplay rear-projection technologies, including DLP, LCD, and LCoS, are most common now, and allow for more lightweight, space-saving designs.

Resolution
The amount of lines and dots (pixels) that make up a TV image. Typically, the higher the number of lines or pixels, the sharper and more detailed the picture will be.

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 Television (SDTV)
SDTV is the baseline display and resolution for both analog and digital. Transmission of SDTV may be in either the traditional (4:3) or wide-screen (16:9) format.

Upconversion
The term used to describe the conversion of a lower resolution to a higher one. This process uses technology to increase the number of pixels, frame rate or scanning lines.

Viewing angle
A TV's maximum usable viewing range from the center of the screen. 180° would be the maximum viewing angle.

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.

Source of glossary terms: http://www.dtvtransition.org