title: why put $ with $self and $body? And is self the same as $self
body: <p>I'm learning jQuery by trying to understand other people's code.  I ran into this:</p>
  
  <pre><code>jQuery.fn.myFunc = function(options, callback) {
  
  //stuff
  
    jQuery(this)[settings.event](function(e) {
      var self = this,
      $self = jQuery( this ),
      $body = jQuery( "body" );
       //etc.
    }
  
  //more stuff
  
  }
  </code></pre>
  
  <p>My understanding is that <code>$</code> refers to the jQuery object.  So why put <code>$</code> with <code>$self</code> and <code>$body</code>? And is <code>self</code> the same as <code>$self</code>?</p>