A UUID can allow players to change their name that is visible to players, without servers and server owners forgetting who the players are. Every player will get a different UUID. Server consoles will see you as your UUID (Server owners can see your UUID as well), while players see you as your custom name. Your custom name is basically like a nick (if you are familiar with /nick you will know what I mean in this sentence), except it will show up in the player list and will show your custom name when you join.When you are banned from a server, your UUID will be banned, not your custom name. So if you change your name, you will still be banned.
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