DVDs and players are encoded to perform only in certain geographical regions. For example, DVDs in North America are encoded "Region 1." Only Region 1 players will play a Region 1 disc. Before you purchase a disc online, make sure that your DVD player can play it.

Region codes in this instance mean flags implemented in DVD-Video discs that determine the geographic area where the DVD-Video disc is being sold and where it can be watched. These codes ensure that one country doesn't get a DVD movie before the same movie is out in that country's theatres. In their corporate omniscience, movie studios have carved the planet into regions with each region having a specific code. All DVD players and discs have region codes. A DVD player and disc must be of the same region or the disc will not play. If you want to watch movies from other countries, you need a multiregion DVD player. This will allow you to play any disc from any region. The region controls are also implemented in PC's DVD-ROM drivers, normally in three levels. First of all, if the DVD-ROM driver is manufactured after 1st of January, 2000, the driver itself has physical locks implemented in it to permit playback of only specific region code. Secondly, all newer operating systems, including Windows 2000 and Windows XP, have region control measurements built-in. And finally, the DVD player software, such as WinDVD or PowerDVD, have region control measurements built-in.

For DVD marketing purposes, the world is divided up into regions. For example, North America is region 1, Europe and Japan are region 2, Hong Kong is region 3, Australia is region 4, etc. To prevent imported disks from competing with domestic releases of the same title, studios often encode their DVD's to be playable only in certain regions. Thus, most disks sold in the U.S. can only be played on region 1 DVD players. Some disks are region free (or region 0), and some DVD players can be modified to disable region codes and play disks from any region.