What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. The probability of generating a duplicate UUID is so close to zero that it is negligible.
Why use Version 4?
There are different versions of UUIDs. Version 4 is completely random (unlike v1 which is time-based). This makes it perfect for generating non-guessable IDs for database keys, session tokens, or file names.