torrents are simple
There is a seed,
this seed is the source for the torrent,
person A comes along, and downloads,
whilst downloading, person A simultaneously uploads,
person B comes along and downloads from both person A and the seed, and while downloading, also uploads, then person C comes along and so on.
I think that\'s right, someone correct me if I am wrong...
at the end of the torrent, the download puts itself together.