Perl is a well-known scripting language that is which is used to make various web-oriented applications, including CGI scripts. One of the features that differentiate it from alternative programming languages is the usage of modules - parts of Perl code which perform predefined tasks and they are widely accepted. Basically, instead of writing custom-made program code to do something or pasting tens and hundreds of lines of program code in the script, you will be able to "call" some module which already exists for this particular job and use only a few lines of program code. As a result, your script will be executed a lot faster since it is smaller. Using modules will, in addition make the script simpler to modify because you will have to browse through much less program code. If you intend to use Perl on your site, you have to ensure that the necessary modules are available on the server.