Introducing ATSC (aka Digital TV or DTV)
ATSC, which some people call digital TV or DTV, uses digital video signals (not analog ones) transmitted by using digital technologies. ATSC is played on televisions that are set up to display these digital signals. Even the connection to the TV itself is digital.
Several years ago, the FCC brought together a big bunch of television industry folks. After a long, painful, and contentious process, the group came up with a new generation of digital TV. This new system — ATSC — follows new, higher-definition television standards.
Even though ATSC is all digital, all the time, televisions designed for ATSC also can connect to good old analog NTSC systems. And some of the stuff coming in over an ATSC system is NTSC. For example, most commercials will probably continue to be taped using NTSC systems for quite some time, and the vast majority of reruns will be NTSC as well (although these NTSC signals will be carried digitally over the ATSC system).
ATSC television standards are different from digital cable or satellite TV. To view them in all their glory, you need to buy a newer, fancier, better, more expensive TV — an HDTV.