About UUIDs
A UUID (Universally Unique Identifier) is a 128-bit identifier standardized by RFC 9562. UUIDs are designed to be unique across space and time without requiring a central authority.
v1 uses timestamp + MAC address. v4 uses 122 bits of randomness (most popular). v7 uses timestamp + random, optimized for database indexing.
Format: xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx where M indicates the version and N the variant.