document ready function when to use code example

Example 1: jquery document ready

// jQuery document ready
$(document).ready(function() {
    
});

Example 2: (function (g, d, a) {})(window, document, jQuery);

;(                                 // <---------------+
                                   //                 | encapsulate the function
  function($, window, document) {  // <--+ declare    | and call it passing three
                                   //    | anonymous  | arguments.
  }                                // <--+ function   |
                                   //                 |
)(jQuery, window, document);       // <---------------+