DVD Region Codes
Global DVD region codes are used as a type of DRM.
Film distributors use the codes to control where DVDs are released, the price, and the content.
For example, a film for Region 1 will not play on DVD players sold in Region 5 areas and will include different content as well as a different price.
In the U.S., the American DVD Copy Control Association is in charge of the regional-playback control (RPC) system.
There are six different regions but DVDs may use multiple region codes or have no restrictions (region all). There are, also, some region-free DVD players. There are also addition region codes not related to regions.