What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier. Version 4 UUIDs are randomly generated and have 122 random bits, making collisions practically impossible.
Format
Standard format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where the 4 indicates version 4 and y is one of 8, 9, a, or b.
Use cases
Database primary keys, API request IDs, session tokens, file names, and distributed system identifiers.