Peer discovery is an essential part of the BitTorrent protocol. It’s how its downloads happen so quickly: You connect to multiple people, and each of them upload a little piece of the file to you. This article explains how the whole BitTorrent DHT peer discovery process works.
If you have a large file you want to distribute to several people – say, a documentary you shot, or your band’s discography – creating a torrent is the way to go. If you make your own torrent, it will speed up the download time for each consumer of your content, provided you and others continue to seed it (remind your friends to be good seeders).