Having root-level access to your server signifies that you can view and change any file on it, which includes important system files. You can also set up software that can change certain settings on the server throughout the, so the installation is possible only if you are signed in as the root user. The aforementioned has full privileges, i.e. you will have full control over your machine at any time and you will be able to do anything you would like. You can also generate other users either with similar rights or with fewer rights, according to what you want them for - day-to-day tasks, other server administrators, etcetera. To be on the safe side, it is generally recommended to employ the root account only when you actually need it and not for tasks you can do through other accounts. You can use a web-based graphical interface or a Secure Shell console in order to connect to the server and to manage it at the root level.