jQuery fn Property
<p>Using e.g. Chrome Developer Tools, we can easily inspect JavaScript / jQuery objects. I am trying to understand the following:</p>

<pre><code>$.ajax    // defined as 'function ...'
$.fn.ajax // undefined

$.removeClass    // undefined
$.fn.removeClass // defined
</code></pre>

<p>Since <code>$.removeClass</code> is not defined, how come we can invoke e.g. <code>$('body').removeClass('some-class')</code>? And, this leads to an error <code>$('body').fn.removeClass('some-class')</code>?</p>
