If you're running a Mastodon server jointly with other people, the admin can assign people roles (such as moderator etc) or create custom roles with specific privileges you have chosen. There is lots more info about this at:
➡️ https://fedi.tips/how-can-organisations-or-groups-run-a-mastodon-server
This roles system can also be used to give your server's supporters a special profile badge, by creating a "supporter" role. You don't have to assign supporter roles any privileges if you just want to give people profile badges.