When you have root-level access to a hosting server, it means that you'll have full control of it. That is to say, you'll be able set up any server-side app whatever the changes that it will make to the software environment on your server, and you will be able to both access and customize any kind of file, including system files, and modify various settings. This can be done by connecting to the server as a root user which has full privileges to perform all these things and also to generate other users, including users that also have full privileges. This particular can be established through a web-based graphical interface or a Secure Shell console. For security reasons, it is recommended that you create a different user for your daily work and employ the root user only when you have to customize the server or to set up software that may be needed by some script-driven application that you wish to run.