Perl is a widely used programming language and one of its main pros is the fact that it supports the so-called modules - short bits of code that contain subroutines and do a number of tasks. The handy side of employing modules is the fact that you don't have to write custom code or add the entire code for a certain task each time it needs to be executed. Alternatively, you can include just one line in your Perl script that calls a certain module, that in turn will execute the necessary action. Not only will this give you shorter and improved scripts, but it will enable you to make adjustments a lot quicker and much easier. In case you aren't a programmer, still you would like to work with a Perl app that you've found on the web, for instance, it's very likely that the app will require specific modules to be already installed on the hosting server.