What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit value used to uniquely identify information in computer systems. It’s often represented as a string of 32 hexadecimal characters, displayed in five groups separated by hyphens, like this:
550e8400-e29b-41d4-a716-446655440000

How does it work?
UUIDs are designed to be globally unique. There are different versions of UUIDs, each generated using different methods:

• Version 1: Based on the current time and the machine’s MAC address
• Version 4: Randomly generated (most common today)
• Other versions: Based on hashing, names, or other specific rules

The probability of generating the same UUID twice is extremely low, making collisions practically impossible.

What is a UUID used for?
UUIDs are widely used in computing whenever a unique identifier is needed, for example:

• Assigning IDs to database records
• Identifying users, devices, or sessions
• Tracking objects across distributed systems
• Generating unique file names or tokens

Unlike sequential IDs, UUIDs can be generated independently across different systems without coordination, which makes them ideal for distributed applications.