BC and AD are abbreviations for before Christ and Anno Domino mean before the Christ's birth after the Christ's birth
Standard DVDs. 1  Region 1: U.S., U.S. Territories, Canada, and Bermuda. 2  Region 2: Japan, Europe (excluding Russia, Belarus and Ukraine), Greenland, South Africa, Swaziland, Lesotho, Egypt and the Middle East. 3  Region 3: Southeast Asia, South Korea, Taiwan, Hong Kong and Macau.
Region code is what movie companies put into DVDs so that people from different part of the world cannot buy DVD from outside of their country. Region 1 is US and Canada only. Like region 2 is for Japan, etc. There are region free DVD players that can play DVD regardless of the region.