About UUIDs

A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. UUIDs are designed to be unique across space and time, making them ideal for use as primary keys in databases or identifiers in distributed systems.

UUID Versions

• UUID v1: Based on timestamp and MAC address
• UUID v3: Based on MD5 hash of namespace and name
• UUID v4: Random (what we generate here)
• UUID v5: Based on SHA-1 hash of namespace and name

Common Uses

• Database primary keys
• Session identifiers
• API keys and tokens
• File names in distributed systems
• Object identifiers in applications