random guid

A Universally unique identifier (UUID) is a 128-bit number used to identify information in computer systems. The term Globally unique identifier (GUID) is also used instead.

How unique is a GUID?

If UUIDs are produced according to standard methods, they will be practically unique without the need for a central registrar or coordination with other UUID manufacturers for authentication. This is unlike most other methods. Although the probability of a duplicate UUID is not zero, it is so close to zero that it can be ignored.

128 bits is large enough and the generation algorithm is unique enough that if 1,000,000,000 GUIDs are generated per second for 1 year, the probability of repetition is only 50%. Or if every human being on Earth produces 600,000,000 GUIDs, there is only a 50% chance of duplication.

How are GUIDs used?

So anyone can create a UUID and use it to identify "something" and make sure that the UUID it generates does not interfere with UUIDs that have been generated before or will be generated later.

Information labeled by UUIDs by independent entities can then be merged together and placed in a database without the need to eliminate interference between identifiers.