If you have root-level access to a server, this means that you will have full control of it. In other words, you'll be able set up any server-side application no matter what the changes that it will make to the software setting on your server, and you will be able to both access and customize any file, which includes system files, and modify various settings. You can do this by connecting to the server as a root user that has full privileges to perform the aforementioned things and also to create other users, which includes users who also have full privileges. This particular can be established with a web-based graphical interface or a Secure Shell console. For security reasons, it is recommended that you create a different user for your everyday work and employ the root user only when you need to modify the server or to set up software which may be needed by a script-driven application that you want to run.