Use "sudo usermod -a -G example_group example_user" to add a user to a group. To add a user to multiple groups at once, separate groups by commas, like "sudo usermod -a -G group1,group2,group3 example ...
When I need to work with Linux user accounts, I tend to default to the command line. Sure, there are GUIs for this purpose, but I find the command line to be more efficient and effective at this task.
Linux is a powerful operating system that also happens to be the most secure platform on the market. With plenty of security features and sub-systems, anyone using the open-source OS can add even more ...