Perl is a well-known programming language and one of its key advantages is the fact that it supports the so-called modules - short bits of code which include subroutines and execute multiple tasks. The convenient side of working with modules is the fact that you do not need to create custom code or add the whole code for a specific process every single time it should be performed. Instead, you can include just a single line in your Perl script which calls a certain module, which in turn will execute the needed task. Not only will this give you shorter and optimized scripts, but it will enable you to make modifications a lot quicker and much easier. If you are not a programmer, still you'd like to start using a Perl application which you've discovered on the Internet, for example, it's very likely that the app will require some modules to be already installed on your web hosting server.