What is User ID in Google Analytics for?

Question

Google

Hello. I have a question. Tracking User ID in Google Analytics should be enabled only if the site has a user's personal account?, just on each site where the User ID is described, they write that each user is assigned a unique id during registration, etc., The general task is to set up the User ID and Client ID. Do I understand correctly that the User ID is needed to track only registered users (from different devices), and the Client ID is for all users who simply visit the site without registration.

Answer 1

Yes that's right.