What is a UUID?
All interfaces must be uniquely identified on a network so that clients can find them. On small networks, the interface's name alone may be sufficient to identify it. However, that is usually not feasible on large networks. Therefore, developers typically assign a Universal Unique Identifier (UUID, interchangeable with the term GUID, or Globally Unique Identifier) to each interface. A UUID is a string that contains a set of hexadecimal digits. Each interface has a different UUID. For details, see String UUID.
The textual representation of a UUID is a string consisting of 8 hexadecimal digits followed by a hyphen, followed by three hyphen-separated groups of 4 hexadecimal digits, followed by a hyphen, followed by 12 hexadecimal digits. The following example is a valid UUID string:
ba209999-0c6c-11d2-97cf-00c04f8eea45
Empty UUIDs are referred to as nil UUIDs rather than NULL UUIDs. The term nil indicates anything that is zero, blank, empty, or uninitialized. An empty string, an empty database record, or an uninitialized UUID are all examples of nil values.
What is Version 1 UUID?
A Version 1 UUID is a universally unique identifier that is generated using a timestamp and the MAC address of the computer on which it was generated.
What is Version 4 UUID?
A Version 4 UUID is a universally unique identifier that is generated using random numbers. The UUIDs from this website were generated using a cryptographically-strong random number generator.
Why use an online UUID generator?
Most programming languages have a simple way to generate UUIDs. But, sometimes you might just need a single UUID and do not want to write any code.
Additionally, we try to make these tools intuitive and explain the differences between the different UUID versions. Testing out the UUID generator above and the UUID decoder will give you a good idea of how UUIDs work and which version to use in your own project or application.
More Information About UUIDS RFC 4122