Having full root-level access means that you will be able to access and modify every file on a specific server, which includes all the system files, and to change system settings or set up server-side software which may be necessary for certain scripts and even offline apps to work appropriately. A server is accessed at the root level with a root user, who has full privileges to perform all the abovementioned tasks. Your root user can also generate various other users. For safety reasons, you're advised to have one more account for day-to-day tasks and to use the root account only if you actually need to perform a task on the website hosting server. The root-level access feature will provide you with full control over your server from any existing location, provided that you know the user credentials.