UUID Version 1
UUID Version 1 identifiers are based on the time of generation and a node identifier (usually the MAC address of the machine). This makes them statistically unique and chronologically ordered (to some extent).
Timestamp
Encodes the date and time the UUID was generated.
Node Identifier
Typically a 48-bit MAC address, ensuring uniqueness across different machines. For privacy, it can sometimes be a randomly generated multicast address.
Clock Sequence
A 14-bit counter to help ensure uniqueness even if the timestamp has the same value (e.g., due to system clock adjustments).
The format of a UUID Version 1 is xxxxxxxx-xxxx-1xxx-xxxx-xxxxxxxxxxxx. The '1' in the third group of hexadecimal digits signifies that it's a Version 1 UUID.
Privacy Consideration
Due to the inclusion of the MAC address, UUID Version 1 can potentially reveal the identity of the generating device. Be mindful of this in privacy-sensitive applications.