[BrunoVT1992]

GUID / UUID v4 and v7 are the two most important versions developers should know today. V4 is the long-standing default built on pure randomness, while v7 is the modern successor that adds a Unix Epoch timestamp prefix for time-based ordering. This page compares their design, strengths, trade-offs and helps you decide which to use.

Quick take: For general-purpose use without ordering needs, v4 remains excellent. For database primary keys, event streams and anything benefiting from time-ordering, v7 is the better choice.