
The following commands must be prefaced with the sudo command. Please see RootSudo for information on using sudo. (sudo is short for “superuser do”).
The addgroup command is used to create a new group in the system. To create a new group, type:
sudo addgroup foobar
The above command will create a new group called foobar.
The adduser command is used to create a new user on the system. To create a new user, type:
adduser foobar
which will create a new user called foobar.
The passwd command is used to assign a new password to a new user or change the current password for an existing user. To add a password or change the password for the user foobar, type:
passwd foobar
For new users, this will generate a prompt to enter the new password. For an existing user, there will be a prompt for the existing password before the prompt for a new password.