Programming Interview Question 1001 – Difference between document load event and document ready event?
A document.ready() function can be more than just one, however there can only be one document.onload() function. A document.ready() function is called as soon as DOM is loaded, the .onload() function is called when everything gets loaded on the page that includes the DOM, images you might have in the page and resources of the page.
Simple summary:
.ready() is called as soon as the DOM is loaded
.onload() is called when everything, including the DOM and other things are loaded