UUID

Universally Unique Identifier (UUID) is a 128-bit long number that is used by Minecraft as a label to distinguish between separate instances.

The following table represents the situations in which UUIDs are used in places accessible by a player:

A player UUID is generated when the user purchases and registers a new Minecraft: Java Edition account. For Bedrock Edition, the Xbox User ID&#91;2&#93; (XUID, or Xbox services ID&#91;3&#93;) is used instead as the unique identifier. Users can also play Java Edition in offline mode with a specified username; the unique identifier chosen for offline mode players is UUID version 3, generated from the MD5 hash of OfflinePlayer:<username>. The community often create sites (most of which are open source) that allow people to search up a name or player UUID to get their skin, player UUID, and name, this is all done with the Mojang API.