what is Torrent?i have heard about it but don't know what is it?please explain.?

[sameer]

torrent is very popular.i don't know what it is but have heard about it.what is u torrent?what is its utility?how can i use it on my com?what do i need to use it?

i have i little idea about it that it is used for downloading stuff?don't' know any thing else about it.from where to down load?

please explain in detail.am ready to read long answers.