When you have root-level access to a server, it indicates that you'll have full control of it. That is to say, you'll be able set up any server-side app irrespective of the changes that it will make to the software setting on the server, and you are able to both access and update any file, including system files, and change any settings. This can be done by connecting to the server as a root user who has full privileges to do the aforementioned things and to make other users, which includes users that also have full privileges. This connection can be established with a web-based graphical interface or a Secure Shell console. For security reasons, it's recommended that you make a different user for your daily work and employ the root user only when you have to modify the server or to install software that may be required by some script-driven app that you want to run.