 UUID/GUID as used by UEFI variables | |
| Acronym | UUID |
|---|---|
| Organisation | Open Software Foundation (OSF), ISO/IEC, Internet Engineering Task Force (IETF) |
| No. of digits | 32 |
| Example | f81d4fae-7dec-11d0-a765-00a0c91e6bf6 |
| Website | RFC 9562 (obsoleted RFC 4122) |
A Universally Unique Identifier (UUID) is a 128-bit label used to uniquely identify objects in computer systems. The term Globally Unique Identifier (GUID) is also used, mostly in Microsoft systems. [1][2]
When generated according to the standard methods, UUIDs are, for practical purposes, unique. Their uniqueness does not depend on a central registration authority or coordination between the parties generating them, unlike most other numbering schemes. While the probability that a UUID will be duplicated is not zero, it is generally considered close enough to zero to be negligible.[3][4]
Thus, anyone can create a UUID and use it to identify something with near certainty that the identifier does not duplicate one that has already been, or will be, created to identify something else. Information labeled with UUIDs by independent parties can therefore be later combined into a single database or transmitted on the same channel, with a negligible probability of duplication.
Adoption of UUIDs is widespread, with many computing platforms providing support for generating them and for parsing their textual representation.
- ^ Davis, K.; Peabody, B.; Leach, P. (2024). Universally Unique IDentifiers (UUIDs). Internet Engineering Task Force. doi:10.17487/RFC9562. RFC 9562. Retrieved 9 May 2024.
- ^ Leach, P.; Mealling, M.; Salz, R. (2005). A Universally Unique IDentifier (UUID) URN Namespace. Internet Engineering Task Force. doi:10.17487/RFC4122. RFC 4122. Retrieved 17 January 2017.
- ^ "Universally Unique Identifiers (UUID)". H2. Retrieved 21 March 2021.
- ^ ITU-T Recommendation X.667: Generation and registration of Universally Unique Identifiers (UUIDs) and their use as ASN.1 Object Identifier components. Standard. October 2012.