What's the purpose of jQuery.fn
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/4083351/what-does-jquery-fn-mean">What does jQuery.fn mean?</a>  </p>
</blockquote>



<p>Part of the jQuery source code states:</p>

<pre><code>jQuery.fn = jQuery.prototype = {
</code></pre>

<p>Given this, wouldn't </p>

<pre><code>$.fn.adamPlugin = function(options) {  
   return this.each(function() {   });  
};
</code></pre>

<p>Be identical to</p>

<pre><code>$.prototype.adamPlugin = function(options) {  
   return this.each(function() {   });  
};  
</code></pre>

<p>If so, what's the point of <code>$.fn</code>?  Adding things to a prototype is fairly common in JavaScript, so I can't quite understand why the jQuery folks would try to abstract this away.  </p>
