If you have root-level access to a server, it means that you will have full control over it. In other words, you'll be able set up any server-side app no matter what the changes that it will make to the software environment on the server, and you're able to both access and customize any kind of file, including system files, and change any settings. You can do this by connecting to the server as a root user which has full privileges to do all these things and also to create other users, including users who also have full privileges. The connection can be established using a web-based graphical interface or a Secure Shell console. For security reasons, it's recommended that you create a separate user for your daily work and employ the root user only when you have to customize the server or to install software that may be required by a script-driven app that you'd like to run.