DVD video players output widescreen video in three different ways:
- Letterbox (for 4:3 screens), which provides horizontal bands at the top and bottom to, in essence, create a widescreen picture in a traditional television set.
- Pan & scan (for 4:3 screens), a version that fills the screen of traditional 4:3 television sets with an entire picture, much like watching network movies.
- Anamorphic or unchanged (for wide screens), which provides a special "anamorphic video" signal that, when processed by a widescreen television set, fills the entire screen and delivers optimum picture quality.
In widescreen or letterbox mode, if a movie is wider than 16:9 (and most are), additional thin black bars will be added to the top and bottom at production time or the sides will be cropped. Video stored in 4:3 format is not changed by the player. It will appear normally on a 4:3 screen. Widescreen systems will either stretch it horizontally or add black bars to the sides.