Developer Reference
UUID Version Guide
Differences between UUID v1, v4, v5 and when to use which.
Universally Unique Identifiers (UUIDs) are 128-bit numbers used to identify information in computer systems. But not all UUIDs are created equal. v4 is random, v1 is time-based.
Random
Generated using random numbers. Most common.
v4
Time
Uses timestamp and MAC address.
v1
Alternative
Sortable alternative to UUID.
ULID
Choose the right version for your database primary keys to balance uniqueness, performance, and security.