"cgi" stands for "common gateway interface", a computer program running on the web server that can be invoked from a WWW page at the browser. A typical use for cgi is the processing of online forms. When the user fills in the fields on the form and clicks the Submit button to sent to the server, the cgi scripts called in the html will be run at the server, and produce results that programmer wants it to do.
Our UNIX web servers have the capability to run CGI scripts. Scripts may be written in Perl, Unix SH, KSH, CSH, and C (NOT C++) languages. Perl is our language of choice as it is a world standard and is well suited to CGI. In addition, Perl code does not require manual compilations whereas C code must be compiled on our web servers prior to use.