Introduction
In Ubuntu, regular users do not have superuser (su) access by default for security reasons. However, you can grant a user permission to switch to the root account using su. This requires adding them to the sudo group and setting a root password.
Steps to Grant su Access
1. Enable the Root Account (If Not Already Enabled)
Ubuntu disables the root account by default. To enable it, set a root password:

Enter and confirm a new password for the root user.
2. Add the User to the sudo Group
To allow a user to use su, they must have administrative privileges. Run the following command:

Replace username with the actual user’s name.
3. Verify the Changes
Log in as the user and try switching to root using:

Enter the root password when prompted. If successful, the prompt will change to #, indicating root access.
FAQs
1. Why can’t I use su in Ubuntu by default?
Ubuntu disables the root account and encourages the use of sudo for security reasons.
2. How do I check if a user is in the sudo group?
Run:
If sudo is listed, the user has admin rights.
3. What’s the difference between su and sudo?
su switches to the root user after authentication.
sudo runs individual commands as root without switching users.
4. How do I disable root access again?
Lock the root account by running: