Universally Unique Identifier - a 128-bit identifier
UUID stands for “Universally Unique Identifier”. The idea is that it’s a Surrogate Keys that function for any element of any table, resource, system, or whatever. It’s universal.
It was developed my Microsoft, and is typically 128-bits. They are supported by Microsoft SQL Server, MySQL, PostgreSQL, MongoDB, and others.
Format
There are 5 Versions of UUIDs. Some are random. Some are time-indexed. They generally are broken into 5 groups of hexadecimal characters, delimited by hyphens. Like so:
123e4567-e89b-12d3-a456-426614174000
What each of those hyphen-delimited groups means depends on the version of the UUID.