When you have root-level access to a hosting server, this means that you will have full control of it. In other words, you'll be able install any server-side app no matter what the changes that it will make to the software environment on the server, and you are able to both access and change any file, which includes system files, and modify various settings. This can be done by connecting to the server as a root user that has full privileges to do the aforementioned things and also to generate 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 make one more user for your daily work and use the root user only when you have to modify the server or to set up software which may be needed by a script-driven application that you would like to run.