Like most Internet phenomena, BitTorrent has its own jargon. Some of the more common terms related to BitTorrent include:
* 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
To understand how BitTorrent works and why it is different from other file-serving methods, let's examine what happens when you download a file from a Web site. It works something like this:
* The Web browser software on your computer (the client) tells the server (a central computer that holds the Web page and the file you want to download) to transfer a copy of the file to your computer.
* The transfer is handled by a protocol (a set of rules), such as FTP (File Transfer Protocol) or HTTP (HyperText Transfer Protocol).
Client-server download process
Peer-to-peer file sharing is different from traditional file downloading. In peer-to-peer sharing, you use a software program (rather than your Web browser) to locate computers that have the file you want. Because these are ordinary computers like yours, as opposed to servers, they are called peers. The process works like this:
* To locate the file, the software queries other computers that are connected to the Internet and running the file-sharing software.
* When the software finds a computer that has the file you want on its hard drive, the download begins.
* Others using the file-sharing software can obtain files they want from your computer's hard drive.
Gnutella's peer-to-peer download process
Unlike some other peer-to-peer downloading methods, BitTorrent is a protocol that offloads some of the file tracking work to a central server (called a tracker). Another difference is that it uses a principal called tit-for-tat. This means that in order to receive files, you have to give them. This solves the problem of leeching -- one of developer Bram Cohen's primary goals. With BitTorrent, the more files you share with others, the faster your downloads are. Finally, to make better use of available Internet bandwidth (the pipeline for data transmission) , BitTorrent downloads different pieces of the file you want simultaneously from multiple computers.
* 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.
To Know More about Installing & configuring BitTorrent, click here.