dvd drives (both in computers and the standalone ones you connect to your tv) Have 'region protection'. When you buy a dvd in whatever country you're in, they are region encoded - i.e. will not play on any player that doesn't have the same region code. for example - i'm in the UK and the region code over here is 2. The vast majority of dvd's sold in the uk are either region free (work in any drive, anywhere in the world) or are region 2, much like the players. The reason for them being region encoded is so that dvd's can't be imported from the USA or Japan. If you crack your drive, you apply a patch which removes/modifies the chunk of code in the dvd drive's firmware (built in software, in a nutshell) that dictates the drive's region code. This will allow you to play discs from anywhere in the world, i.e. get dvd's cheap, or before they're released in your region.