So can someone explain these terms?

[SSJBartSimpson]

I know seeders are a good thing. But why exactly, and how do you get something to have more seeds? And what is a leech? And what are peers? Surely if a file says you have 10 peers there aren't 10 other people in the world downloading that file.

[paintball9]

http://www.utorrent.com/documentation/beginners-guide

http://btfaq.com/serve/cache/23.html