This article is about how to add a user to a group in Linux.
The instructions will work well on most Linux distros, including Ubuntu, CentOS, Debian, Fedora, Linux Mint, etc.
Users are arranged into different groups on all Linux-based systems. The whole idea behind this is that it makes the administration of the system easier, as the users can be arranged into different groups and can be granted different permissions as required by the system administrator. The same user can be included in different groups, and the same file can be given different permissions based on the groups.