First, we will begin with some quick definitions.
What is a plug-in?
A plug-in is basically something you attach to your website to make it perform a function. These functions can vary from serious functions such as an ecommerce plug-in or a security plug-in, to less serious ones, such as a pop-up plug-in or a floating bar plug-in. Think of plug-ins as ornaments, and your website as a house. Get the picture?