Ways to Initialise Jquery

jquery-init

// Below one, runs the function when the DOM tree is built
$(document).ready(function({
  // Codes goes here
});

$(function() {
  // Codes goes here
});

// Runs the funciton right away
(function($){
  // code
})(jQuery)

// same as

jQuery(function($) {
  // Codes goes here
});