$(document).ready()

window.onload()

Execution Point:
$(document).ready() event occurs after the HTML document (DOM) has been loaded. window.onload() event occurs later, when all content (e.g. images, frames) also has been loaded.
DOM vs JQuery:
ready event is specific to jQuery. onload event is a standard event in the DOM.
Quicker:
Execute before onload() Execute after ready()
Requires JQuery:
Yes No
Syntax:

//Load JQuery first before execution
$(document).ready(function){
//Code goes here
}
OR
$(function){
//Code goes here
}

window.onload(){
//Code goes here
}
#Usage
We can have multiple usage on page Can be used only once on page