How Torrent Works

How Torrent Works

BitTorrent
 BitTorrent is a protocol that enables fast downloading of large files using minimum Internet bandwidth. It costs nothing to use and includes no spyware or pop-up advertising.

Unlike other download methods, BitTorrent maximizes transfer speed by gathering pieces of the file you want and downloading these pieces simultaneously from people who already have them. This process makes popular and very large files, such as videos and television programs, download much faster than is possible with other protocols.


BitTorrent Speak
Like most Internet phenomena, BitTorrent has its own jargon. Some of the more common terms related to BitTorrent include:

* Leeches - People who download files but do not share files on their own computer with others

* Seed or seeder - A computer with a complete copy of a BitTorrent file (At least one seed computer is necessary for a BitTorrent download to operate.)

* Swarm - A group of computers simultaneously sending (uploading) or receiving (downloading) the same file

 * .torrent - A pointer file that directs your computer to the file you want to download

* Tracker - A server that manages the BitTorrent file-transfer process

Here's how it works:

BitTorrent's peer-to-peer download process

* You open a Web page and click on a link for the file you want.

 * BitTorrent client software communicates with a tracker to find other computers running BitTorrent that have the complete file (seed computers) and those with a portion of the file (peers that are usually in the process of downloading the file).

* The tracker identifies the swarm, which is the connected computers that have all of or a portion of the file and are in the process of sending or receiving it.

* The tracker helps the client software trade pieces of the file you want with other computers in the swarm. Your computer receives multiple pieces of the file simultaneously.

* If you continue to run the BitTorrent client software after your download is complete, others can receive .torrent files from your computer; your future download rates improve because you are ranked higher in the "tit-for-tat" system.

Downloading pieces of the file at the same time helps solve a common problem with other peer-to-peer download methods: Peers upload at a much slower rate than they download. By downloading multiple pieces at the same time, the overall speed is greatly improved. The more computers involved in the swarm, the faster the file transfer occurs because there are more sources of each piece of the file. For this reason, BitTorrent is especially useful for large, popular files.