The window object represents an open window in a browser. If a document contain frames (), the browser creates one window object for the HTML document, and one additional window object for each frame. Note: There is no public standard that applies to the Window object, but all major browsers support it.
The navigator object contains information about the browser. Note: There is no public standard that applies to the navigator object, but all major browsers support it.
When an HTML document is loaded into a web browser, it becomes a document object. The document object is the root node of the HTML document and the "owner" of all other nodes: (element nodes, text nodes, attribute nodes, and comment nodes).
The Element Object In the HTML DOM, the Element object represents an HTML element. Element objects can have child nodes of type element nodes, text nodes, or comment nodes.