Perl is a widely used programming language and among its major advantages is that it works with the so-called modules - short pieces of program code that include subroutines and do numerous tasks. The practical side of working with modules is the fact that you won't have to write custom code or add the whole code for a certain process each time it has to be executed. Instead, you are able to include only one line in your Perl script which calls a certain module, that in turn will perform the necessary task. Not only will this provide you with shorter and more optimized scripts, but it'll also help you make changes quicker and easier. If you are not a programmer, still you'd like to begin using a Perl app that you've found on the worldwide web, for instance, it's likely that the application will need certain modules to be already installed on the web hosting server.