wixUsers.currentUser.Id - How is the ID generated?

I’m using wixUsers.currentUser.Id to get the current users ID.

How is this ID generated by Wix?

It is generated the first time, then stored on the users PC in a cookie? Is it based on their IP address etc?

I’m curious because I’ve noticed that my User.ID on a live published site, is always the same, it doesn’t change after closing and reopening my browser or even a full restart of the PC.

Thanks for any feedback, much appreciated.

Cheers,

Andy.