The default installation of Ubuntu Server is non-graphical, the server is managed from the command line. Reasons for this type of installation are security and elimination of resource heavy GUI's (Graphical User Interface's). On some installations, the system management ease of a GUI makes life a little easier for the system administrator. It is possible to install the web based system management tool without the GUI. This method will allow you to use those tools locally on the server without using a separate computer on the network.
Tools to be installed are a lightweight window manager, a method of locking the screen, web based system management software, web browser and a light weight file manager.