Because browsers like Netscape and Internet Explorer communicate using HTTP (the protocol for sending HTML documents), your application must be able to interpret HTTP requests and return an HTTP response to the browser. This is where your CGI program comes in.
8.3.2.3 Using the C$GETCGI routine
8.3.2.4 Stripping carriage returns from CGI input
8.3.2.5 Processing the user's request
8.3.2.6 Generating the HTML output
8.3.2.7 Using the DISPLAY statement