Perl is a widespread programming language and among its key pros is the fact that it supports the so-called modules - short pieces of program code that contain subroutines and perform multiple tasks. The useful side of using modules is that you don't need to create custom program code or add the entire code for a particular task every single time it should be performed. Instead, you'll be able to include only a single line in your Perl script which calls a particular module, that in turn will perform the necessary task. Not only will this give you shorter and enhanced scripts, but it will allow you to make modifications quicker and much easier. In case you are not a programmer, still you would like to work with a Perl app which you've discovered on the Internet, for instance, it is likely that the application will need some modules to be already installed on your hosting server.