Having full root-level access signifies that you can access and update any kind of file on a selected server, which includes all the system files, and to change system settings or install server-side software that may be needed by specific scripts and even offline apps to function effectively. A server is accessed at the root level via a root user, which has full privileges to do any of the aforementioned tasks. Your root user may also generate other users. For security reasons, you are advised to have one more account for day-to-day tasks and to use the root account only if you actually need to do some task on your website hosting server. The root-level access function gives you full control of your server from any kind of location, provided that you have the user credentials.