The Element object provides a variety of powerful DOM methods for interacting with DOM elements — creating them, updating them, traversing them, etc. You can access these either as methods of Element itself, passing in the element to work with as the first argument, or as methods on extended element instances:

// Using Element:
Element.addClassName('target', 'highlighted');
 // Using an extended element instance:
$('target').addClassName('highlighted');

Element is also a constructor for building element instances from scratch, see new Element for details.

Most Element methods return the element instance, so that you can chain them easily:

$('message').addClassName('read').update('I read this message!');

More Information

For more information about extended elements, check out "How Prototype extends the DOM", which will walk you through the inner workings of Prototype's DOM extension mechanism.