Having full root-level access signifies that you'll be able to access and change any kind of file on a specific server, in addition to all of the system files, and to change system settings or set up server-side software which may be required by specific scripts and even offline applications to function effectively. A server is accessed at the root level with a root user, who has full privileges to do all of the abovementioned things. The root user may also create other users. For safety reasons, you're advised to have a separate account for everyday tasks and to use the root account only if you actually need to do a task on the server. The root-level access feature will provide you with full control of your server from any kind of location, provided that you have the user credentials.