About
BitTorrent is both a Protocol and one of the softwares that uses that protocol. It enables P2P file-sharing.
It works through .torrent files that contain metadata on the file (or files) you want to share, and the tracker (or trackers) associated with that files. A tracker is just a webservice that keeps your IP address (and socket) and gives it to the other people who are sharing/downloading the same file as you (and the other way around).
Although a torrent may have multiple trackers, it’s still a centralized system. But nowadays, clients already suport DHT, which means they try to connect to other peer without a tracker, making it really P2P.
People who already have the file completed and are still connected are called seeders and those who are still downloading are called leechers. Usually trackers have a minimum ratio limit (per torrent if a public tracker, or per account if it’s a private one) that’s Uploaded/Downloaded data.
Legal problems.
Using BitTorrent is NOT illegal! In fact, I suggest you to use it when sharing large files among a lot of people. That’s the case of some linux distributions that also use BT to share their ISOs. And you can download it legally! In the “large files” categories you also find video and games. That might or might not be legal! In this case the law varies from country to country, and in Portugal is illegal to share files that you do not have license to redistribute (it seems that you are not infracting the law by downloading, but in BT when you download a file, you are also sharing the parts you already have!). However I can use BitTorrent to make backups (although there’s not much advantage in using it) since you have the right to make a private copy of whatever you own. And you can also share anything that is either made by you, or is in the public domain, which I encourage you to do.
For more information about the legality of BitTorrent and related topics, I suggest you follow ThePirateBay’s blog.
BitTorrent applications:
- uTorrent (Windows)
- Transmission (Mac, Linux and BSD)
BitTorrent trackers:
- Mininova
- ThePirateBay
- Nipponsei (Anime OSTs)
- Anime-P2PT A Portuguese anime-related community with a private tracker and a public one (both made by me) and that are LEGAL!
Other Resources:
- Anime-P2PT BitTorrent FAQ (written by me in Portuguese)