Disclaimer : The contents of this writeup should not be considered as an express mandate to download contents from the internet illegally. The author does not take the guarantee of a legal or a virus free download. Piracy is illegal and warrants appropriate actions against the perpetrator of crime by the regional government.
Downloads have a very high percentage share in the internet usage today. It could be anything from ebooks to movies, music, software or virtually any digital content available on the internet. Many of the different protocols(protocol, in laymans terms, is the way computers communicate with each other on the network)being used for file transfer online are HTTP, FTP, P2P etc. Bittorrent is the latest of all this protocols using P2P technology, and has taken over the world of downloads by constituting about 43% of the downloads on the internet. But it has been hard for people to use this technology, since the way it works seems a bit complicated for many who are used to traditional downloading protocols. Lets delve deeper…
Bittorrent download operation basically consists of two sets of file download. The first file is called as the torrent file which contains all the information of the file/files to be downloaded along with the information of the tracker(or the servers which sees through the file transfer. Once the file(which usually is about few kbs) is downloaded, it has to be opened in a download client which supports bitTorrent protocol. The most popular among them is BitTorrent and utorrent. Other file sharing softwares have started incorporating bitTorrent and can be used for such downloads. Once you run the torrent file using this download client, your actual download starts.
The file being download is not hosted on any single computer. In fact, it may not be hosted on any central server at all. People like you and me can create a torrent file and share it. The important factor is the tracker, or the computer which keeps the check of the status of each torrent file on multiple computers and facilitates the file sharing between them. The downloadable files are divided into several pieces and every other piece my be download from different hosts.
To begin with the download, one may have to avails the services of a torrent indexing site like torrentz.com, or go directly to the websites hosting the torrent files(like the monova, mininova, btjunkie etc.). Once you download the required torrent file, you are good to go about using the torrent client. Note that each of the page containing the torrent file also gives the information, authenticity, quality(in case of movies) etc. about the file you are about to download. Such information is fed in by the users who have already downloaded the file, and its quite useful to check it out before downloading the file.
There are two types of computers on a bittorrent network, seeder and leechers. Seeders are those computers which either seed a new torrent(seeding means keeping a file for others to download), or which seeds the file after finishing downloading themselves. Leechers are the computers which only download a file but do not share it. Bittorrent networks have tried many possible ways to thwart the leeching attitude. One way is by keeping the record of the upload to download ratio of a particular peer(peer is the computer connected in the bittorrent network), which should ideally be 1. This means that the peer has uploaded all the contents which he has downloaded.
For the download to be fast enough, the torrent should have a large number of seeders, which will be disclosed by the sites which host the torrent files. Once you start downloading, you become one of the seeders( you have the option of reducing the seeding bitrate if you are using pay per use connection, but multiple attempts to download in this fashion can lead to a blacklisting of your IP address).The success of bittorrent depends on the number of people sharing the files.
As I said earlier, the file being downloaded is divided in to large number of packets, and different packets may be downloaded from different peers. Also, once a packet is downloaded on your computer, it is shared automatically and any peer which has not downloaded that particular packet, can upload it from your computer. This goes on continuously till the entire download is complete and you wish to stop that particular torrent. Once you stop it, your computer is no longer a seeder for that particular torrent.
All being said, I should remind you that this technology has largely been used for sharing material illegally across the internet. Any movie of software that you come across on the internet may not be a version that can be distributed freely. Also many times, viruses are spread in the disguise of genuine content. Users should take care about that.
So go ahead. Bite the torrent!!