Torrents, also known as BitTorrents, are a form of P2P, or peer-to-peer (or person-to-person - there are many variations) file transfers. Torrents make it possible to share and receive software, movies, music, and iBooks. Basically, torrents download tiny "bits" of files available from different sources on the Internet, all at the same time. In general, torrents are free for users with no limitations on the files available, they practice extensive quality control to reduce the risk of fake or corrupted files, and encourage true P2P file transferring by rewarding users who generously share, or seed, their files and punishing those who put limitations on file sharing from their computers.
Torrents also usually practice a "warming and tracking" philosophy and means of operation. The act of swarming refers to splitting large files into smaller pieces; the smaller bits are then shared between a "swarm" of users looking for the same particular file. When the torrent server aids users to find each other within the same swarm, it is called tracking. The reward and punishment systems work like this: if a user is stingy about sharing his or her files, downloading lots of files without sharing his or her own with the torrent masses, the tracking servers slow down the user's downloading speed. When a user freely shares the files on his or her computer, the tracking servers will reward that user by significantly increasing his or her uploading speed, which can produce a huge amount of bandwidth.
Every swarm member the tracking server finds is placed into a category, wherein users who have only part of a file are labeled as "leeches" or "peers" and users who have the complete file as known as "seeds." The more seeds in the swarm the faster the download and upload. When a user completes his or her download but remains connected to the torrent server so that others can have access to files, it is called "seeding" and, within the torrent world, is considered an act of supreme good karma.
Al Munroe writes on topics such as Torrent, BitTorrent and P2P File Sharing for The Tech FAQ.
