Users browse the web to find a torrent of interest, download it, and open it with a BitTorrent client. The client connects to the tracker(s) specified in the torrent file, from which it receives a list of peers currently transferring pieces of the file(s) specified in the torrent. The client connects to those peers to obtain the various pieces. Such a group of peers connected to each other to share a torrent is called a swarm. If the swarm contains only the initial seeder, the client connects directly to it and begins to request pieces. As peers enter the swarm, they begin to trade pieces with one another, instead of downloading directly from the seeder.
This review is merely for the protocol itself and not the piracy that has been attached to it. BitTorrent is a protocol... basically a set of rules on how something should behave. You go on the Internet using a protocol called TCP and IP. In the days of 14.4k modems and the like, the basic way to get information through the Internet was to connect to a single computer/server and get the information. That's how we get on Google, Lunch and … more