Raw DOM element vs. jQuery object

Question

I'm looking at the following example of explicit iteration from http://jqfundamentals.com/chapter/jquery-basics:

$( 'li' ).each(function( index, elem ) {
  // this: the current, raw DOM element
  // index: the current element's index in the selection
  // elem: the current, raw DOM element (same as this)
  $( elem ).prepend( '<b>' + index + ': </b>' );
});

The comments refer to elem as a raw DOM element, but then the code calls .prepend() on elem.

I'm just getting started with jQuery, but it's my understanding you can only call a jQuery method on a jQuery object - not on a raw DOM element. Am I misunderstanding?

Answer 1

This could be helpfull..

var test = document.getElementById('test') //returns a HTML DOM Object
var test = $('#test') //returns a jQuery Object
var test = $('#test')[0] //returns a HTML DOM Object