Bit torrent is a completely decentralized p2p where all users download stuff from each other...basically thats it. To use it, download the.torrent (which are very small) of the file you want. Atleast one person has to have it seeded which means there must be atleast 1 person with the whole file on their computer. Then by using a Bit Torrent client you load the torrent and that connects to the people that have the file on their computer and it downloads it from them. And while you are downloading, it uploads too so everyone is always getting and receiving something. The more people that have a certain file means you will get it faster. You can go to Google and find the different clients. There is the official one, Azureus, Sharaza, BitTornado, and some other ones. Azureus is the coolest but I don't have the link offhand so Google is your friend. Hope that helps. If anyone can explain it better, please go ahead.