Jquery is a great library, it makes manipulating DOM element and browser really simple and easy. As a web developer, jQuery is our day to day tool. However, sometimes it just too convenience that we forget how to make web page without it. It is important to go back to see how jQuery handle and wrap the DOM api and provide the simple interface for us.
Angular.js comes with a simple compatible implementation of jQuery, called JQLite. JQLite is used internally for angular.element if user doesn’t include jQuery, as a replacement for jQuery. It only have 1000 lines of code with lots comments, So it’s a good starting point to understand how jQuery works.