Having full root-level access signifies that you'll be able to access and customize any kind of file on a specific server, including all the system files, and to change system settings or install server-side software that may be necessary for specific scripts and even offline apps in order to work appropriately. A server is accessed at the root level with a root user, which has full privileges to perform all of the aforementioned tasks. The root user can also create various other users. For security reasons, you're advised to have another account for everyday tasks and to use the root account only if you actually need to perform a task on your hosting server. The root-level access feature will give you full control of your server from any kind of location, as long as you know the user credentials.