Perl is a widely used programming language and one of its major advantages is that it works with the so-called modules - short bits of program code which contain subroutines and perform a number of tasks. The handy side of employing modules is the fact that you will not need to create custom-made code or include the entire code for a certain task each time it should be executed. Alternatively, you can add just one line in your Perl script which calls a certain module, which in turn will execute the needed action. Not only will this give you shorter and optimized scripts, but it will also allow you to make modifications swifter and much easier. If you are not a programmer, yet you would like to use a Perl application which you've found on the web, for example, it is likely that the application will need specific modules to be already set up on the hosting server.