Version 4 (recommended)

The most commonly used version of UUID based on random numbers. It has a low probability of generating duplicate UUIDs and does not expose any information about the system.

Version 5

Based on the SHA-1 hash and a namespace identifier, it generates the same UUID for the same input.

Version 3

Based on the MD5 hash and a namespace identifier, it generates the same UUID for the same input.

Version 2

Based on the current timestamp and MAC address of the device. It was designed to be used for DCE (Distributed Computing Environment) security.
However, it has been deprecated due to security risks.

Deprecated

Version 1

Based on the current timestamp and MAC address of the computer on which it was generated.