Region codes were invited to control where moves were distributed so the film companies could maximize profits and releases using economical geography. There are nine codes for DVDs. Strange Maps has a map of the six geographical zones. The other zones include 0 (works in any DVD player), 7 (screener copies of DVDs, invented to fight Chinese movie piracy), and 8 (international venues like airplanes, cruse ships, etc). Most computer DVD-viewing software can play any region while hacking is necessary to reformat one's DVD player to be region free.
B: Middle East, Europe, Africa, Australia, and New Zealand
C: Russia, People's Republic of China, India and a few others