Perl is a well-known scripting language that's designed to make various web-oriented applications, such as CGI scripts. One of the attributes that differentiate it from many other programming languages is the usage of modules - batches of Perl program code which complete predefined tasks and they're universally accepted. In simple terms, as an alternative to generating tailor-made code to make something or pasting tens and hundreds of lines of program code inside your script, you'll be able to "call" some module that is already available for this particular task and use only a couple of lines of code. Therefore, your script will be executed faster since it'll be smaller. Using modules will additionally make the script much easier to change as you will have to search through a smaller amount of program code. If you'd like to use Perl on your site, you have to make sure that the necessary modules can be found on your server.