When you have root-level access to a server, it indicates that you will have full control of it. In other words, you can set up any server-side application whatever the changes that it'll make to the software setting on your server, and you will be able to both access and change any kind of file, which includes system files, and modify any settings. This can be done by connecting to the server as a root user who has full privileges to perform all these things and also to generate other users, which includes users who also have full privileges. The connection can be established with a web-based graphical interface or a Secure Shell console. For safety reasons, it is recommended that you make another user for your everyday work and use the root user only when you have to modify the server or to install software which may be required by a script-driven application that you'd like to run.