The two main standards used in HDTV broadcasting are:
720p (720 lines of resolution scanned progressively) is one of the HDTV standards. As such, ABC and FOX, have committed to 720p as their HDTV broadcasting standard. 720p provides a very smooth, film-like image due to its progressive scan formula. Also, even though 720p is considered high-definition, it takes up less bandwidth than 1080i, which is covered next.
1080i (1,080 lines of resolution scanned in alternate fields consisting of 540 lines each) is the most commonly used HDTV format, and has been adopted by PBS, NBC, and CBS (as well as satellite programmers HDNet, Showtime, and HBO through special feeds) as their HDTV broadcast standard.
In addition, 1080p, in which 1,080 lines of resolution are scanned progressively, is also in use, providing the most detailed high definition video image that is currently available.
However, since 1080p is not a part of the FCC's approved over-the-air HDTV broadcast standards, for that programming, it is displayed as a result of on-board video processing in a 1080p capable TV or Video Projector.
In order to receive or display HDTV signals, you must have an HDTV.
