GUID vs UUID
GUID means globally unique identifier. UUID means universally unique identifier. In everyday engineering conversation, the terms usually describe the same 128-bit identifier written as hexadecimal groups such as 2f4a9d1e-9b6f-4a4e-9d8a-6a8d6d7c4a10.
The word GUID appears often in Microsoft ecosystems: C#, .NET, SQL Server, Active Directory and Windows APIs. The word UUID appears more often in standards documents, web APIs, databases and distributed systems.