- Browser shows the document containing the form.
- User enters the data into form and click submit button.
- Script in browser will perform client side validation.
- Browser decodes URL and contacts server.
- Server translates the URL into a path and a file name.
- Server realizes that URL point to a program.
- Server prepares its environment variables and launch the scripts.
- Script executes and reads environment variables and STDIN.
- script sends appropriate MIME header to STDOUT for content.
- Server send rest of its output to STDOUT and terminates.
- Server will notify the termination of script and closes the connection to browser.
- Browser displays the output from the script.
CGI normally resides in a directory called CGI-bin.
When a script is invoked by a server, the server passes the information to script via environment variables.
