Tracker is a server that gives and receives client information when it is uploading or downloading files. Generally, one torrent file has several trackers that have information on the number and address of the client underneath. So, the more tracker for a file, the more client information can be contacted, especially seeders. The more seeders, the faster the download. If you download a file via torrent, usually not all tracker for the file is recorded on the client. Some torrent clients usually provide facilities to increase the number of trackers for files being downloaded.
Generally, for every download job, the torrent client will limit the number of connected peers, usually to 50 peers. You can increase the number of peers connected to your client beyond this limit, for example to 100. Just a note, do not add too many peers, for example, 500 or 1000 or exceeds the number of peers for the file itself. Adding too many peers will cause the downloaded data to be defective.