what is the purpose of Element Object in Extjs?

->Element wraps most of the DOM methods and properties that you'll need, providing a convenient, unified, cross-browser DOM interface (and you can still get direct access to the underlying DOM node when you need it via Element.dom)
->The Element.get() method provides internal caching, so multiple calls to retrieve the same object are incredibly fast
->The most common actions performed on DOM nodes are built into direct, cross-browser Element methods (add/remove CSS classes, add/remove event handlers, positioning, sizing, animation, drag/drop, etc.)