A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify some object or entity on the internet. Depending on the specific techniques used, a UUID can be generated entirely randomly, or it can incorporate certain components such as a timestamp or MAC address to make it unique. The UUID is divided into two halves: the most significant 64 bits and the least significant 64 bits.

The most significant 64 bits are generally used to store information such as the timestamp and version of the UUID, while the least significant 64 bits are used to store the variant of the UUID and other random or unique bits[^0^][^2^][^7^].