What is UUID?
A UUID (Universally Unique Identifier) is a 128-bit value, usually written as 32 hex digits in five hyphenated groups, designed to be unique across systems without central coordination. Version 4 UUIDs are random; version 7 UUIDs embed a timestamp prefix so they sort chronologically, which makes them friendlier as database primary keys.
Example
f47ac10b-58cc-4372-a567-0e02b2c3d479 — a version-4 UUID.
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