Question 1

What is a UUID?

Accepted Answer

UUID (Universally Unique Identifier) is a 128-bit identifier standard (RFC 4122). It's commonly used in databases, APIs, and distributed systems to uniquely identify resources without central coordination.

Question 2

What is the difference between UUID v1 and v4?

Accepted Answer

UUID v1 is time-based and includes the machine's MAC address. UUID v4 is randomly generated and is the most commonly used version. v4 provides better anonymity.

Question 3

Are generated UUIDs truly unique?

Accepted Answer

UUID v4 has 122 random bits, making collision probability astronomically low (~1 in 2.7×10¹⁸). For all practical purposes, they are unique.