2. root

In Linux, certain administrative tasks require elevated privileges. These privileges belong to a special account known as the root user in Linux. While you can log in directly as root, it is often safer and more manageable to gain superuser access temporarily.

The su Command

Besides the sudo command, you can use su (substitute user) to gain superuser privileges. When run without a username, su attempts to open a new shell session for the linux root user, prompting you for the root password.

su

You can also use this command to switch to any other user on the system, provided you know their password.

Risks of a Persistent Root Shell

Using su to open a root shell has significant downsides. Operating continuously as the root user increases the risk of making a critical, system-altering mistake. Furthermore, actions performed in a root shell are not logged under your personal user account, making it difficult to audit system changes. For these reasons, it is best practice to use sudo for individual commands that require superuser access.

The sudoers File

So, how does the system determine who is allowed to use sudo? Access is controlled by a configuration file located at /etc/sudoers. This file lists the users and groups who are granted permission to run commands as the superuser.

To edit this file safely, you should always use the visudo command. This utility opens the sudoers file in a text editor and performs a syntax check before saving, which helps prevent configuration errors that could lock you out of administrative access.