To run function onLoad
jQuery(window).on("load", function(){
..code..
});
To run code onDOMContentLoaded (also called onready)
jQuery(document).ready(function(){
..code..
});
or the recommended shorthand for onready
jQuery(function($){
..code.. ($ is the jQuery object)
});
onready fires when the document has loaded
onload fires when the document and all the associated content, like the images on the page have loaded.