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