DVD is the first video format (apart from a few Japanese laserdiscs) to take full advantage of 16 x 9 TV's capabilities.

A 4 x 3 TV set picture is made up of approximately 480 horizontal lines of resolution from the top of the screen to the bottom. A laserdisc or video tape letterboxed at 2.35:1 uses only around 270 of those lines of resolution to display the picture; the other 210 lines make up the black bars you see at the top and bottom of the screen.

On an Anamorphic DVD disc, that same 2.35:1 letterboxed image is stretched vertically to use all 480 lines of resolution. (If you were to look at that image without any further processing, all of the actors would appear unnaturally tall and thin.) Then, the special circuitry in the 16x9 TV set squeezes those 480 lines of picture back down to the proper size. In effect, a picture that would be made up of 270 lines of resolution on a regular 4 x 3 TV set is made up of a full 480 tightly-spaced lines on a 16 x 9 set, resulting in finer detail than regular TVs can display.