window.onload vs document.onload

window.onload

• It is fired when the entire page loads, including its content (images, css, scripts, etc.)
• $(window).load()

document.onload

• It is fired when the DOM is ready which can be prior to images and other external content is loaded
• In general, document.onload event is fired before the window.onload
• $(document).ready()

Also Read:

1. Default function parameters
2. Passing arguments from one function to another in javascript
3. css: margin does not work
4. Why use javascript strict mode
5. position:fixed