Perl is a popular programming language and among its main pros is the fact that it works with the so-called modules - short bits of code that contain subroutines and execute a variety of tasks. The practical side of employing modules is the fact that you don't have to write custom program code or include the whole code for a particular task each and every time it should be performed. Alternatively, you can add only one line in your Perl script which calls a given module, that consequently will execute the needed action. Not only will this provide you with shorter and improved scripts, but it'll also enable you to make changes a lot quicker and much easier. If you aren't a programmer, but you would like to start using a Perl app that you've found on the web, for instance, it is very likely that the app will require certain modules to be already set up on your web hosting server.