What is UUID?
UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify information in computer systems. The probability of generating the same UUID twice is practically zero.
UUID Format
A UUID is 32 hexadecimal digits in 5 groups: xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx • 8-4-4-4-12 format (36 characters) • M = version, N = variant
UUID Versions
Version 1: Time-based + MAC address Version 4: Random (most common) Version 7: Unix timestamp + random (newest)
Example
550e8400-e29b-41d4-a716-446655440000Use Cases
• Database primary keys • Session identifiers • Distributed system IDs • API request tracking