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What is a GUID?
GUIDs (Globally Unique Identifier) and UUIDs (Universally Unique Identifier) are 128-bit numbers represented by hexadecimal text, for practically unique values across distributed systems. "UUID" is the global standard (RFC 4122 and its successor, RFC 9562), while "GUID" is Microsoft's term (predating RFC 4122) for essentially the same identifier.
How are GUIDs used?
GUIDs are essential for enterprise software developers, progammers, engineers, database administrators, and testers in systems and application development and quality assurance. They are used in Java, C#, Python, C++ , SQL and non-relational databases keys, versions, and component identifiers, or just about anywhere a unique identifier is required without central coordination.
How unique is a GUID?
128-bits is big enough and the generation algorithm is unique enough that if 1,000,000,000 GUIDs per second were generated for 1 year the probability of a duplicate would be only 50%. Or if every human on Earth generated 600,000,000 GUIDs there would only be a 50% probability of a duplicate.
More Information About GUIDs
Globally Unique Identifier - Wikipedia, the free encyclopedia
GUID Structure - Microsoft.com
RFC 4122