title: jQuery expando properties
body: <p>I have a question on jQuery expando properties. Basically I would like to understand in VERY simple terms:</p>
  
  <ol>
  <li>How this whole process works like how jQuery adds the expando property, </li>
  <li>what is the criteria to add it to any element</li>
  <li>What is the exact reason which makes jQuery lightweight</li>
  <li>What exactly does the jQuery cache have?</li>
  </ol>