Having full root-level access signifies that you'll be able to access and change each file on a specific server, which includes all of the system files, and to change system settings or set up server-side software that may be needed by certain scripts and even offline applications in order to work appropriately. A server is accessed at the root level with a root user, which has full privileges to perform any of the abovementioned things. The root user can also make various other users. For safety reasons, you're advised to have another account for routine tasks and to use the root account only if you actually need to perform a task on your hosting server. The root-level access attribute will provide you with full control of your server from any existing location, as long as you know the user credentials.