Linux allows you to create separate user accounts and control which groups and permissions are assigned to them. User management commands normally require root privileges or access through sudo.

Create a new user

To create a new user with a home directory, run:

sudo useradd -m username

Replace username with the name of the user you want to create.

Next, set a password for the new user:

sudo passwd username

Enter the new password when prompted and enter it again to confirm.

Note:
If you are already logged in as root, you can run these commands without sudo.

Add a user to a group

To add an existing user to one or more additional groups, run:

sudo usermod -aG group1,group2 username

Replace group1 and group2 with the groups you want to assign and username with the corresponding user name.

Attention:
Use the -a option together with -G when adding supplementary groups. Running usermod with -G without -a replaces the user's existing supplementary group membership.

Check user information and groups

To view the user ID, primary group, and supplementary groups assigned to a user, run:

id username

You can also display only the user's group memberships with:

groups username

Lock or unlock a user account

To lock password authentication for a user account, run:

sudo passwd -l username

To unlock it again, run:

sudo passwd -u username

Delete a user

To delete a user account while keeping its home directory and files, run:

sudo userdel username

To delete the user together with the user's home directory, run:

sudo userdel -r username

Attention:
The userdel -r command removes the user's home directory and its contents. Make sure you have backed up any required data before using it.