The point is, that a Linux system can include hundreds of users (if necessary). Although you wouldn't want this, a Linux server can handle 4,294,967,294 concurrent and distinct users.

How to create a restricted group and add users on a Linux server The first thing we must do is create a new group and add users to it. Create the group with: sudo groupadd restricted ...

Here's a quick guide to adding users and groups, and then how to add users to groups, all from the command line on the Linux platform.