Aspect Ratio
Aspect ratio comes in two basic forms - Standard aspect ratio 4:3 and Widescreen 16:9.
Standard 4:3 means the shape of the picture is four units wide for every three units high. The standard NTSC television broadcast is almost square.
Widescreen is similar to how movies appear in the theater, where their aspect ratio is 16 units of width for every 9 units of height. Letterbox is the effect that occurs when a movie shot in widescreen is played on a regular picture tube, leaving black bars on top and bottom. Widescreen 16:9 TVs are better suited for this type of presentation. A widescreen TV doesn't necessarily mean you won't have any black bars on top and bottom, but it does mean you'll get a picture that is closer to theatrical display.
It's always better to use widescreen format and any new big screen TV purchased today should be 16:9 aspect ratio. The demand for widescreen TV is such that more and more content is being made and even broadcast in wider formats.
