The different DVD regions are geographical areas which have been assigned to one of six regions worldwide. There are two regions reserved for special use and one universal, or uncoded, region.
All DVDs and DVD players sold within a region are made to work only in that area. Therefore, a DVD coded for one region cannot be played on a player coded for a different region. As an example, the United States, along with Canada, is in region 1, and all DVD players sold in the United States are built to play only region 1 DVDs. Likewise, all DVDs sold in the United States are encoded as region 1 DVDs and are playable only on region 1 DVD players. Some DVDs, however, are uncoded or region 0, which allows them to be played anywhere.
There are also region-free DVD players available, particularly in areas outside of the United States. In order to prevent region 1 DVDs from being played on these players, a regional coding enhancement was developed. This additional coding scheme is applied only to region 1 DVDs.
DVD region codes were developed to help protect the rights of copyright holders and film distributors. By restricting where DVDs can be played and by what devices, movie studios have more control over theatrical and DVD release schedules.