Adding Users to Linux Groups and User Management | Pluralsight

It’s important to introduce two files that we will be using as examples of adding users to a group in Linux.

In the /etc directory, the passwd and the group files hold all of the users and group information. These files are essential when logging on to the system, and you’ll need to know them if you ever take a Linux exam. Anytime you add a user to a group in Linux, that user is added to the passwd file.

The /etc/group file holds all of the group information, as well as the users belonging to each group. The structure is very similar to that of /etc/password.