BitTorrent is a peer-to-peer file-sharing protocol. It is used to distribute large files or blocks of files via the Internet. It is often used to distribute videos and MP3s, but is also used to distribute software, images and various other kinds of data. BitTorrent uses a system by which every recipient of a file uploads portions of the file they've already downloaded to newer recipients. The result is a reduced strain on the original provider in terms of bandwidth, but it also makes the process more efficient, providing multiple sources for a file instead of just one.

A Brief History
BitTorrent is a networking protocol invented by Bram Cohen. At the time he was working for MojoNation. MojoNation had a product for encryption that would take an encrypted file and break it into smaller pieces. These pieces would then be distributed to other computers. If someone wanted to decrypt the file they would have to simultaneously download all the pieces from many computers. http://www.oreillynet.com/pub/a/python/2003/7/17/pythonnews.html Bram Cohan quit his job in 2001 to work on BitTorrent full time.http://www.wired.com/wired/archive/13.01/bittorrent.html?pg=1&topic=bittorrent&topic_set= At this time he wanted to help distribute large files over the internet like Linux distros. He got bata testers for BitTorrent program in the summer of 2002 by distributing free pornography on the network. http://en.wikipedia.org/wiki/Bram_CohenAt this time the only method of internet distribution was direct download or the Client Server model. This was very slow and costly. In 2004 BitTorrent the Company was founded.http://kepler.ss.ca.gov/corpdata/ShowAllList?QueryCorpNumber=C2676150

Although the BitTorrent protocol is ostensibly designed for legal file distribution, many users and web sites have used it to distribute and download unlicensed content, violating the copyrights of the owners of the content. The MPAA has been particularly vocal and active in combating this kind of use, playing key roles in the closure of several torrent tracking sites that provides such content. BitTorrent Inc. maintains that their protocol is intended for legal uses, and have formed several content distribution deals with 20th Century Fox and other legitimate content providers.