The user root is the primary administrative user on your Virtual Private Server. In order to modify many system files, including adding or modifying users, you must be root.
Because root is such an important user with so much power, you should be especially careful about selecting a root password and maintaining its security. For help selecting a secure password, see the Password Security page.
Although you may occasionally need to, it is not the best practice to connect directly to your Virtual Private Server as the user root. Instead, any user who belongs to the wheel group can SSH to the server, then use the su command to become root. It is also important to remember never to use an insecure protocol such as Telnet, even if you aren't connecting directly as root. Any non-encrypted data could be sniffed by malicious hackers.
Because the root user should only be used for administrative purposes, root does not have E-mail or Web permissions.
The root user has a special ability called Super User (or su). This allows authorized normal users to become the root user, or it allows the root user to become another user. Only members of the wheel group can use the su command to become root, and even they will be required to enter the root password. Once you become root, however, you can use the su command to become another user on the server without requiring a password.