DEVELOPER GUIDE
GUID vs UUID: is there a difference?
In everyday development, GUID and UUID usually describe the same kind of 128-bit identifier. The terminology mostly reflects platform history.
The short answer
UUID is the standards-oriented term; GUID is especially common in Microsoft technologies. A conventional value contains 32 hexadecimal characters displayed in five groups. Braces and uppercase letters are formatting choices.
Versions matter more than the name
Version 4 uses random bits and is a common choice for independently generated identifiers. Time-ordered versions can improve database locality, while name-based versions deterministically derive an identifier from a namespace and name.
Collisions and security
No finite space makes collisions impossible, but correctly generated version 4 UUID collisions are extraordinarily unlikely for ordinary systems. Use a cryptographically secure platform API rather than a homemade random routine.
A UUID does not prove authenticity, hide information or replace a database uniqueness constraint.