^^ also adding to my comment further
A tracker is just a medium for all the peers to be held collectively together, the tracker in many cases (like tracker for uTORRENT) dose not knw the type of files wich are being shared b/w ppl (or users to be more precise) but just makes sure that where ever the PEER is holding that part of the file or the file in whole, they shud all be connected together and share the parts for a common purpose (known as seeding+leeching) ..
U can think of it as a McDOnald's shop,

whre all ppl come to eat and SHARE their views and then wen the conversation is over on that common topic, they all move to their respective plzces or routes..

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Also, i was able to find out wat advantage the ADD PEER gives wen d/loading a torrent file.. well as such there is NO advantage coz as it is the BitTORRENT (the application s/ware which uses helps to d/load torrent files, eg: uTORRENT) will eventually connect to the NEWEST PEER as soon as it gets itself connected to it..
To say in simple terms..all the PEERS which are the MOST active and MOST likely to have a good connection speed are chosen by the bitTorrent client..
(the only SMALL advantage being that, the bittorrent client on ur PC will eventually connect itself to that PEER which was ADDED by the "ADD PEER" command without any significant increase in speed, coz it depends on the PEER's connectivity)
Cheers n e-peace....