Stands for "High Definition Television". A kick ass video format with resolutions of 720p (1280x720 pixels progressive), 1080i (1920x1080 pixels interlaced) and 1080p (1920x1080 pixels progressive). Can be up to 6 times the quality of standard definition video. Using a proper HDTV (not an EDTV) viewing medium, it can be as good as looking through a window.
If you cannot get high definition television channels in your area, purchase a WMV HD DVD. Visit www.wmvhd.com for more info.
Stands for "Enhanced Definition Television". Has a resolution of 480p (852x480 pixels progressive). Most DVD players today are able to output a progressive signal, meaning that DVDs can be displayed in 480p. Much better than standard definition TV, but still not as good as HDTV. Think hard before purchasing an EDTV viewing medium, as HD-DVDs and the increasing number of HD channels will make you regret the decision not to get a proper HDTV.
480p is a step up in picture quality from standard definition TV, but still cannot provide that extra crispness and detail found with proper HD video (720p and above resolution).