Torrents on the other hand are a little different. This word is given to anything that utilizes multiple connections for a user to download a file. So instead of you connecting to one server to download something, you are now connecting to any number of different computers each with the same file to download a piece of the file from each computer until the download is finished.
So, when you see a torrent and it has the words seeds and peers(or leeches), the seeds are people who have the entire file on there computer and are uploading (essentially a dedicated server for the file) and peers or leeches are people who are downloading the same file and uploading the part that they have already (so not a full source of the file, but can still use their upload band for you to download the file).
And finally, torrents are not illegal. They are perfectly legitimate and I believe were originally used by napster as a way for them to not have to have large dedicated servers and large upload sizes. The act of torrenting is completely legal, and is why clients like uTorrent and Limewire still exist and make money. It is the files that you torrent that is illegal. Things like copyrighted music and movies.
