The term 720
p refers to 720 lines of
progressive video (720 lines
per frame). Higher resolution than standard DVD, which is 480i or
480p. Usually refers to 1280x720 resolution in 1.78
aspect ratio.
[Source:
LG Guide to HDTV]
See also HDTV.
Also see Webopedia's "Did
You Know...All About Digital TV . DTV and HDTV".