BitTorrent is an open source, peer-to-peer method of delivering content more efficiently. The technology does not use traditional sharing files, but rather bits of files that add up to a whole. In essence, one peer has a particular file and acts as a seed node. The seed node then breaks the file into a number of pieces of equal size and distributes them to several other peers that are seeking to obtain the file; each peer receives one piece. Those other peers then exchange pieces with each other until each peer has obtained a full copy of the original file.
Because the seed node sends only one copy of the file — in pieces, to the other peers — the “sharing” process is more efficient and requires less bandwidth than if the seed node had to send a full copy of the file to each of the other peers. BitTorrent’s ability to conserve bandwidth in this manner makes it feasible to download much larger files — such as computer operating systems, movies, and television programs — that are more cumbersome to share using other P2P file-sharing programs.
BitTorrent thus harnesses the numerous individual Internet connections maintained by its users, rather than relying on a single, central pipeline, to distribute large files “cheaply and quickly,” and the efficiency of that peer-to-peer network is dependent directly on Internet users’ ability to establish TCP connections for both downloading and uploading content. Although once relegated to serving, in most cases, the savviest Internet users with unsavory or even unlawful purposes, BitTorrent and other peer-to-peer technologies, such as Gnutella, have entered the mainstream. New online content distributors, such as Vuze, Inc., rely on BitTorrent to distribute video programming to millions of online viewers legally, as do several established distributors such as CBS, Twentieth Century Fox, and Sports Illustrated.
The search mechanism for BitTorrent also works differently than the search mechanism in the original Napster or in a FastTrack application. Instead of searching other users’ hard drives, a BitTorrent user must search for a website that has the so-called “torrent” file associated with the file the user ultimately wants to download. The “torrent” file contains information about the location of the computer with the seed node for a particular file, and the location of the server, known as a “tracker,” that is currently coordinating the exchange of pieces of that file. Clicking on the “torrent” file allows a BitTorrent user to join this exchange process. As soon as the user downloads a piece of the desired file, BitTorrent automatically begins uploading that piece to other users who are looking for that file.