Peers refer to the number of users that have the file and are seeding (sharing). If the torrent file has a healthy number of peers, it should result in faster and more reliable file transfer and a quality streaming experience. If your torrent file has zero or few peers (i.e., few people are sharing the file), you may experience buffering, or may not be able to view the file at all.
To monitor the number of peers after you have started a torrent stream, look to the bottom of the player window and count the number of active peers (seeders). If you run into problems with the quality of the stream, or the media cannot play at all, it may be due to a low number of peers, or no peers at all. If this is the case, try to find a different torrent file or keep the existing torrent file and try again later. You might find that more seeders come online, and the file becomes more available to stream.