Having full root-level access means that you can access and customize each file on a particular server, which includes all the system files, and to change system settings or install server-side software which may be necessary for specific scripts and even offline apps in order to function effectively. A server is accessed at the root level via a root user, which has full privileges to perform all of the aforementioned tasks. The root user may also make other users. For safety reasons, you're advised to have a separate account for day-to-day tasks and to use the root account only if you actually need to do a particular task on your server. The root-level access feature will give you full control over your server from almost any location, provided that you know the user credentials.