A DVD duplicator is a stand alone machine built specifically to copy discs. It has one a DVD drive to read the source disc, and at least 1 burner to create the new copy. Common examples would be 3, 5, and 7 burners, all simultaneously burning copies of the original. unlike a computer which uses programs and processing power to copy discs, a duplicator has everything it needs to know on a single controller which is installed in a drive bay. Burns tend to be faster than with a computer, due to being able to burn on the fly without crashing. (Note that some computers can manage this too, it depends on issues like speed, processing power, not multitasking, etc.) One important thing to remember with a duplicator though, is that it won't copy an original movie, the controller doesn't remove copy protection. Unless you're authoring your own DVDs for distribution, there's not alot of point in a duplicator for home use, since it's useless for legally backing up your original movies.
