The typical data flow for a perl script serves a web page looks like this:

 Web browser  ---->  Web server ----->  +--------+
              HTTP               CGI    | Your   |
                                        | Perl   |
                                        | script |
 Web browser <----- Web server <------  +--------+

CGI refers to a protocol for exchanging data between the web server and your perl script. (It is not the CGI perl module).

There are other methods for communicating between a perl script and a web server, popular ones include FastCGI and mod_perl.

So, for answering the question whether your program runs a CGI script you have to look into the configuration of your web server. Using the CGI Perl module doesn't change that, it just makes your program simpler.