DVD and Blu-Ray Mechanics
DVD Region Codes
Commercial DVDs contain encoding that limits DVD player compatibility based on geography. The encoding for a particular DVD is designated as a region code, a number generally from one to six. A region code is assigned to a DVD to protect copyright and to help prevent piracy.
Region Code Map
There are a few ways to view a DVD that is encoded with a region code outside of your geographic location.
Most software DVD players (those that are installed on a computer) can be changed to match the region code of the disc you would like to view. This procedure comes with an important caveat! You are normally limited to changing the region code a few times before your final choice is locked in and therefore can not be changed.
Another option is to use the VLC Player, a free download for both Windows and Apple computers (see link at top right). While the controls can take some getting use to, this software application is a reliable means of viewing DVDs from around the world.

A Blu-ray Disc (BD) is an optical storage medium similar to its predecessor the DVD. Blu-Ray discs are the same size as DVDs and contain 25 GB per layer. Dual layer discs, which can store 50 GB, are used for most feature-length movies.
Blu-Ray in the Classroom
As our classroom DVD players are upgraded, they are being replaced with Blu-Ray players. It is important to note that Blu-Ray players are backward compatible with DVDs. You do not have to buy the Blu-Ray version of a movie to view it in classrooms with upgraded players.
What is the difference between a Blu-Ray disc and a DVD?
The primary advantage of Blu-Ray technology is the greatly increased disc capacity which provides enough space to store high quality content and high definition versions of films. This content is generally too large for standard DVDs and requires a higher capacity storage medium.
DVD players use a red laser to read and write data. The Blu-Ray format uses a blue-violet laser (the 'blu' in Blu-ray). A blue-violet laser has a shorter wavelength than a red laser, which makes it possible to focus the laser with greater precision. This feature allows data to be packed more tightly and stored in less space. It then becomes possible to fit more data on the medium even though Blu-Ray discs are the same physical size as DVDs.

