CGI Gateway, Common Gateway Interface, is a standard mechanism for communication between Web servers and server-side gateway programs.These gateway programs are written either in a compiled language such as C or in an interpreted language such as Perl.Common Gateway Interface (CGI) allows Web servers to run scripts or programs on the server and send the output to the client Web browser. Graphical User Interface: GUI makes the user interaction with the computer system more interactive. Graphical User Interface is a computer interface that allows users to interact with a device through graphical elements such as pictures and animations, as opposed to text-based commands.Text-Based User Interface: A text-based user interface displays text, and its commands are usually typed on a command line using a keyboard.Command-Line Interface: CLI stands for Command-line Interface. It is a means of interacting with a computer program. It is a text-based user interface used to manage and view computer files.