OOP lets coders make templates for objects: the classes. then, when they want to implement one, the call upon an instance of that object. so you can make var win1 = new Window(); and var win2 = new Window(); with only defining what a window should be and those two snipits of code. The new objects inherit the characteristics of the class. This allows for quick changes in a window.EG: a window has a width and height. in you code, you dont use OOP. You make 30 windows, each unique, by hand. Alot of code for making each object. The boss rolls by, and says whoops, windows now need an address as well. now you have to go back and individually change each one. in OOP, you just have each of the 30 an instance of the class window, and when you need to add address, you do it in the class definition. You might not see the advantage now, but try writing apps, not webpages. You will see the advantage.