When you have root-level access to a server, it indicates 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'll make to the software setting on the server, and you are able to both access and update any kind of file, including system files, and change various settings. This can be done by connecting to the server as a root user who has full privileges to perform all these things as well as to make 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 make a different user for your daily work and employ the root user only when you need to customize the server or to set up software which may be needed by a script-driven app that you wish to run.