Bit Torrent is type of peer-to-peer file sharing network. It can be used to share any kind of file. Since the files are shared by peers, this type of file sharing can be quicker and cheaper than other methods. In general bit torrent sharing works likes this: Files with the ".torrent" extension are downloaded, the ".torrent" files are loaded into a bit torrent client and in the client is where the full file is downloaded from peers who already have all, or part, of the file.
Clarification on Legality of Bit Torrent Use
It's not illegal to use bit torrents to download legitimately free software. There are several free programs, movies and music shared with bit torrent programs that are completely legal to download. It's only illegal when you use the program to download copyright protected work.
The misdemeanor penalty for downloading copyrighted works is significantly less than a felony. Anyone charged with a misdemeanor can face up to one year in jail and $100,000 in fines. This is the smallest charge that can be brought against you for downloading copyrighted material.
If you're caught downloading copyrighted works, and you're charged with a felony, the penalty is far more severe. A first-time felony charge can include up to five years in jail and a $250,000 fine. To be charged with a felony, four criteria must be met: the work must be copyrighted, you must have acted of your own will, you distributed or reproduced the copyrighted material and you made it accessible for others to download.
Felonies and Bit Torrents
It's important to note that if you're downloading copyrighted material via bit torrents, you are almost certainly committing a felony. This is due to the way bit torrents are inherently set up. When you download something with a bit torrent program, you're also automatically making it available to others, even if you don't have the whole file yet. This means you're distributing the copyrighted material and making it accessible for others to download.
Like any crime, the penalty for a repeat offense is more harsh. The fine stays the same, but you can face double the prison time if you're caught downloading copyrighted material more than once.