Pillarboxing
From WSGFWiki
Definition
Pillarboxing is a specific behavior of 4:3 pictures on widescreen monitors. When a 4:3 DVD is played on a widescreen monitor, black bars are visible on the left and right of the picture to make it fit the shape of the screen. The wider the screen, the larger the black bars need to be. This behavior is referred to as pillarboxing, and can occur in games as well as movies.
Pillarboxing is not specific to 4:3 images. As long as the screen is wider than the picture, pillarboxing is possible. For example, a 16:10 image could be pillarboxed on a 16:9 monitor.
Examples
Classic movies (pre-1954) such as King Kong, pictured below, are usually 4:3. So are most independant films and TV shows. Their DVDs will appear pillarboxed when played on a widescreen monitor.
Most widescreen monitors have an auto-aspect ratio option. Using this will automatically pillarbox games that do not support widescreen, such as Diablo 2.
