UUID

A UUID (universally unique identifier) is an arbitrary 128-bit identifier, and a standard set of guidelines for generating such an identifier. The goal is that each identifer will (with overwhelming probability) be unique, without need of a central authority.

Some of the bits in a UUID are obviously not random. They are used to indicate the UUID version number, etc.

The standard way to display a UUID is to use hex encoding, with four hyphens added at particular positions. It typically looks something like this: 00000000-1111-2222-3333-444444444444

The Microsoft version of UUID is known as GUID. ''[TODO: Explain the difference between UUID and GUID. Supposedly there is a difference in endianness, but what exactly does that mean?]''

Links

 * RFC 4122
 * Universally unique identifier
 * Globally unique identifier