What is the difference between analog, digital and high definition television?

Analog television
This what you see "over-the-air" or with an antenna today. This technology was developed in the 1940s and 1950s. It's the "free" television broadcast you would see if you plugged in any TV and flipped through the channels. These broadcast signals do not require cable or satellite service, but depending upon where you live, these services may enhance your viewing capabilities. By law, all analog television transmissions will cease once the digital conversion is complete on February 17, 2009.
Analog TVs will continue to work with cable, satellite, VCRs, DVD players, camcorders, video games consoles and other devices for many years.

Digital television (DTV)
DTV is modern technology which offers a dramatically clearer picture, improved sound and the capability for broadcasters to air programs in high definition and send out multiple signals, also known as multicasting, through sub-channels.

After February 17, 2009 this will be the only "free" television broadcast that's available. To receive the DTV signal, televisions will need to be digital-capable or have a set-top box converter.

High Definition Television (HD, HDTV or Hi-Def)
In addition to a digital transmission, some programs will also be available in high definition. The Hi-Def programs will have a larger picture like in a movie theater, the best available picture resolution, clarity and color. Hi-Def programs also have Dolby theatre surround-sound capabilities.

To watch programs in Hi-Def you will need:
1. A television equipped to display pictures in Hi-Def. The Hi-Def ready television screens are wider than the traditional television screen.
2. An antenna that can receive digital, Hi-Def signals over the air. Or, cable/satellite Hi-Def service.

Sources:
dtv.gov
Find out more about the DTV transition at dtvtransition.org

[ Return to Digital TV Home ]