To be more precise, high-definition refers to an image with either 1,080 horizontal lines scanned in an "interlaced" fashion (the scanner goes up and down, hitting the even lines one way, the odd lines the other way) or 720 horizontal lines that are scanned "progressively" (all the lines get hit up and down). These methods are designated 1080i and 720p. By comparison, analog television is scanned at 480i, and non-HD digital television is scanned at 480p. (DVDs get scanned at 480i by a standard DVD player and at 480p by one with a progressive-scanning feature. You need a digital TV for the latter to make any difference.) EDTV's resolution is 480p. On an EDTV, high-def broadcasts will look as good as DVDs, but standard-def programs may look quite bad. DVDs will look good, though not as good as on an HDTV. (HDTVs have internal "scalers" that convert all images to HD images. Converted HD is not nearly as good as the real thing, but it is an improvement.) To check if a TV is HD or ED, look at the technical specifications. Under "resolution," you'll find the number of vertical pixels and horizontal pixels (for example, 840x480 or 1020x768). If the smaller number is lower than 720, you're looking at an EDTV. If it's higher than 720, it's HDTV. Some companies are starting to produce televisions that scan at 1080p—this is the beginning of ultra-high definition.

With more and more television broadcasts in high-definition and HD-DVDs hitting the market sometime soon, it's shortsighted to spend thousands of dollars on an EDTV that will be obsolete within just a few years. Still, if you yearn for a plasma but can't afford HDTV, the Panasonic TH-42PD25, which lists for $2,995 but can be had for as little as $2,200, probably offers the best ED picture.