Actual difference between active users and registered users

What is the difference between "Active users" and "Registered users"?

An "Active user" is any user in your LMS who can sign in concurrently. For example, "25 active users" means that only 25 users can login to your LMS instance at the same time. Logged in users who are idle for an hour will be logged out and removed from the active users count. You can also manually logoff users in 'Account & Settings' --> 'List users' page under user options.

A "Registered user" is any user who has an user account in your LMS instance. You can have unlimited registered users created.