Perl is needed for CGI-Scripts.
Just search the web for perl cgi tutorials.
Perhaps you might also like to look at PHP.
Thank you Vrythramax,. Yes I will check cgi tutorial in order to learn cgi scripting.
what is the difference between PERL and CGI?
CGI stands for Common Gateway Interface, as I understand it allows for a webserver to start up a script and hand it some information (The name of the page, GET and POST data...). It then outputs everything outputted from stdout to the webserver.
Perl stands for Practical Extraction and Reporting Language, it has existed since before the internet. Since it is a scripting language that's been around for a long time it is commonly deployed through CGI.
For your information, PHP is implemented through CGI here at frihost, this is probably due to the greater security features that CGI offers over the apache module.