A DVD is an object and can not be transmitted via the internet. The movie, however, can be. Normally it's compressed into a different format, such as XviD, an .avi. There are many file sharing programs out there. However, bittorrent is probably the most popular. There are many popular bittorrent sites out there but thepiratebay.org is one of the most popular. Bittornado is a good bittorrent client. Simple to use, doesn't require many system resources.