1.jQuery is far and away the most popular DOM library
Used to allow modification and control of the DOM
A more uniform way of interacting with the DOM
2.All based around the dollar symbol
Add to a page by simply including it as a file using a script element <script src="http://cdnjs.cloudflare.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
3.It’s best to choose whether to use a framework based on the specific project
jQuery is a large file to introduce to a page and slow the downloading of that page, particularly on mobile browsers with potentially weak connections.