How to add user to a group?

To add a user to a group in Linux, you can use the usermod command. Here’s how to do it:

Open a terminal.
Run the following command (replace username with the user's name and groupname with the name of the group):
```
sudo usermod -aG groupname username
```
- -aG: This option appends the user to the specified group without removing them from other groups.
Verify the change by checking the groups the user belongs to:
```
groups username
```

This will list all groups that the user is a member of, including the newly added group. If you have any more questions, feel free to ask!