- If this is an existing users
Syntax: usermod -a -G groupname username
For example: usermod -a -G sudo myadminaccount -> this will make myadminaccount belong to sudo group , this mean it can run sudo su – to becom a root.
- For new user ( you haven’t created it yet)
Syntax: useradd -G groupname username
This will add a new username to a group name groupname