What is DVD Region Encoding?

The DVD Region Code system is a method of Digital Rights Management, the practice of controlling DVD movies and digital properties after sale. The Region system controls which countries DVD movies will play in. This is achieved by way of region-locked DVD players, which will play back only DVDs encoded to their region (plus those DVDs without any region code or with all region 0 encode).
Most IHF DVDs are region 0 encoded so that they will play on all DVD players worldwide.

List of Region Codes and Countries:

0	This informal term means "worldwide". Region 0 is not an official setting; discs that bear the region 0 symbol either have no flag set or have region 1-6 flags set.
1	Canada, United States; U.S. territories; Bermuda
2	Europe (except Russia, Ukraine and Belarus); Western Asia; Egypt; Japan, South Africa, Swaziland, Lesotho; French overseas territories; Greenland
3	Southeast Asia; South Korea; Taiwan; Hong Kong; Macau
4	Mexico; Central and South America; Caribbean; Australia; New Zealand; Oceania
5	Ukraine; Belarus; Russia; Africa (except Egypt, South Africa, Swaziland, Lesotho and French overseas territories); Central and South Asia; Mongolia; North Korea
6	People's Republic of China; Hong Kong
7	Reserved for future use (found in use on protected screener copies of MPAA-related DVDs and "media copies" of pre-releases in Asia)
8	This "region" refers to international venues such as aircraft, cruise ships, etc.