Perl is a very popular scripting language that is employed to build different web-oriented apps, which includes CGI scripts. Among the attributes which differentiate it from other programming languages is the employment of modules - batches of Perl code which perform predefined tasks and they are widely accepted. Basically, instead of creating custom-made program code to do something or pasting tens and hundreds of lines of program code in your script, you are able to "call" some module which is already available for this specific task and use just several lines of program code. Due to this, your script will be executed a lot faster because it will be much smaller. Using modules will additionally make your script much easier to modify as you'll have to go through much less code. If you want to use Perl on your website, you have to ensure that the required modules are available on the server.