High Definition Television can display images and videos with a higher quality than those found in a standard television, and therefore the details in a gaming experience can increase quite dramatically when played on an HDTV set.
Additionally, more and more broadcast television channels and cable channels are being offered in HDTV format. Currently, HDTV formatted programs and games are offered in 720p (Progressive scan of 720 vertical scanning lines) and 1080i (1080 interlaced vertical lines), but 1080p (Progressive scan of 1080 vertical lines) will soon be available.
Basically, the larger the number of vertical lines, the better a picture will look.
Interlaced versus Progressive scan: Interlaced is fine for still or slow moving images, however, the best high speed video will be viewed with a Progressive scan model or setting.