Definition The “root” account on a Linux computer is the account with full privileges. Root access is often necessary for performing commands in Linux, especially commands that affect system files. Because root is so powerful, it’s recommended to only request root access when necessary, as opposed to logging in as the root user. This can help prevent accidental damage to important system files.
How to become root user in a VPS or dedicated server
Type su - and press ↵ Enter. This will attempt to log you in as “super user.” You can actually use this command to log in as any user on the machine, but when left blank it will attempt to log in as root. after typing command su – it will ask for the root password , Enter the root password and you can now have the root access to your server or VPS