Letterboxing
From WSGFWiki
Definition
Letterboxing is a specific behavior of widescreen pictures on standard monitors. When a widescreen DVD (anamorphic or not) is played on a 4:3 monitor, black bars are visible on the top and bottom of the picture to make it fit the shape of the screen. The wider the picture, the larger the black bars need to be. This behavior is referred to as letterboxing, and can occur in games as well as movies.
Letterboxing is not specific to 4:3 TVs. Anamorphic 16:9 pictures will be letterboxed on 16:10 monitors too, and anamorphic pictures wider than 16:9 will be letterboxed on 16:10 and 16:9 monitors, but the black bars won't be as large as they would be on a 4:3 TV.
Examples
Western films such as A Fistful of Dollars (as pictured) often have very wide aspect ratios, much wider than a 16:9 monitor. As a result, when the DVDs are played on a 4:3 TV, the letterboxing is profound.
Many games feature letterboxed cut-scenes for a cinematic look and feel, including games that lack widescreen support such as Diablo II.
