I need help understanding this script.

I need help understanding this script.

Im following a tutorial and the person did not explain it well enough and Im pretty lost!
So if you can just tell me what jQuery is doing!


  1. <body>

  3.     <h1>My Website</h1>

  5.         <button data-file="day">Day</button>
  6.         <button data-file="night">Night</button>

  8.         <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js" ></script> 

  10.         <script>

  12.         (function() {
  13.             var link = $('link');

  15.             $('button').on('click',function(){
  16.                 var $this =$(this),
  17.                     stylesheet = $this.data('file');

  19.                 link.attr('href',stylesheet + '.css');

  21.                 $this
  22.                     .siblings('button')
  23.                         .removeAttr('disabled')
  24.                         .end()
  25.                     .attr('disabled','disabled');
  26.             });
  27.         })();

  29.         </script>
  30. </body>