Having full root-level access signifies that you'll be able to access and modify any file on a particular server, which includes all of the system files, and to change system settings or set up server-side software that may be necessary for specific scripts and even offline applications to function properly. A server is accessed at the root level through a root user, which has full privileges to perform any of the aforementioned things. Your root user may also make various other users. For security reasons, you are 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 specific task on your website hosting server. The root-level access feature gives you full control over your server from almost any location, provided that you have the user credentials.