Having root-level access to your server signifies that you will be able to view and modify any file on it, which includes important system files. You may also install software that can update particular settings on the server throughout the, so that the installation can be performed only if you are logged in as the root user. The latter has full privileges, which means that you will have full control over your machine whenever you want and you can do anything you want. You can also generate other users either with similar rights or with fewer rights, depending on what you require them for - day-to-day tasks, other server admins, etcetera. To be on the safe side, it's generally recommended to use the root account only when you really need it and not for tasks that can be done via other accounts. You may use a web-based graphical interface or a Secure Shell console to connect with the server and to manage it at the root level.