So I'll start, but since I'm doing this live, I retain the right to edit it.
BitTorrent involves sharing; tit for tat. Your sharing ability, is limited by your upload speed (upstream) which is usually considerably less than your download (downstream) speed, and the percentage of that available bandwidth that you are willing to use to share the file.
Unlike other file sharing types, where you have to have the full file in order to share, with BitTorrent, if you have any of the full pieces of the file, you can start to share those pieces with users who don't have those bits, and you can get bits of the file from them, that you don't have. The piece size is generally 256KB's, but could be 128KB's or even 512 or larger/smaller. In a healthy swarm, the persons with the fastest upload speeds, and who are using that speed, will be favored by the seed or seeders (swarm members with the full file) since they are giving back more pieces faster than some others, thus taking some of the load off of the seeder. So, a good thing to remember is that if you want the file faster, share faster. There is nothing more miserable for a seeder to watch, than to be seeding a file to leechers (swarm members that don't have the complete file) and seeing that they are not sharing between themselves. This effectively turns a seeder into a server, dishing out the complete file to every leecher, which totally defeats the purpose of BitTorrent. Which brings me to the second definition of a leecher: A swarm member who is not sharing. I would advise everyone to open the Tab "Peers" and watch a large swarm in action. It will be a learning experience if you have never done this. All for now, feel free to add, subtract, edit or debate.
