Document = Webpage
Object = Elements of a program
Model = Way of thinking about things

DOM is a way to describe HTML or XML documents in an Object-Oriented fashion (i.e. Having objects inherit from their parents, and having different level where each level has its modules). DOM is an API (Application Programming Interface), the majority of the famous browsers support the W3C DOM.

Window		(Each frame in the page can be a Window)
|____Navigator	(Firefox, IE, Chrome...etc)
|____Screen 	(PC screen, Mobile screen,...etc )
|____History	(the list under the "Back" button)
|____Location	(URL)
|____Document	(Current open page)
	|
	|____HTML
	       |____Head
	       |      |____Title
	       |            
	       |____Body
	            |____p
	            |	 |____em
	            |	 |____strong
	            |____...
	            |____...

Note: Check the Firefox DOM Inspector to get to know the object hierarchy of an HTML document.

Objects in JavaScript

1. What does it look like, characteristics? Properties
2. How does it perform, functionality? Methods
3. How does my script control it? Event Handlers

cat an Object
cat.fur a Proprety
cat.purr( ) a Method

document.form = Nouns of JS
window.open = Verbs of JS