Yeah, Wegas have the normal 4:3 screen size ratio, but I know what you're talking about because I asked the salesman the exact same question when I went tv shopping with my dad last week. Basically if you're watching a normal tv broadcast (non high definition) on a widescreen tv (16:9 screen size ratio), then you can either choose to keep the image in its 4:3 ratio with black bars on the sides or you can stretch the image as described next. The salesman explained to me that if you were to imagine three circles side by side going across the tv, then "stretch mode" stretches just the outer two circles but keeps the center one the same. So, basically the geometry of the image in the center of the screen remains perfect, but the image along the left and right sides become slightly distorted. I guess some people would rather look at a slightly distorted picture than put up with two black bars.