If I’m not mistaken, torrent uses trackers to look for seeds and peers, to initiate downloads. If syncthing works similarly, it probably also uses trackers to look for seeds and peers for our “torrent” with our files. Or something similar where the program asks if the given “user” exists. Can this “server” be moved to my own server?
There are no trackers; there are discovery servers and relays. You can search for those terms to figure out more. Neither of those are involved with the actual data synchronized.