Perl is a well-known scripting language that is used to build different web-oriented applications, which includes CGI scripts. Among the characteristics which distinguish it from various other programming languages is the usage of modules - parts of Perl program code which complete predefined tasks and they're commonly accepted. In simple terms, rather than creating custom-made code to make something or pasting tens and hundreds of lines of code inside your script, you are able to "call" a module that already exists for this particular job and use just a few lines of program code. Due to this, your script shall be executed quicker because it will be smaller. Using modules will, in addition make your script much easier to change as you'll need to go through a smaller amount of program code. If you wish to use Perl on your site, you should make sure that the necessary modules are available on the server.