For downloading jQuery files visit link given below: - http://jquery.com/
Ajax is method to use for exchanging data from client to server in asynchronously way without updating whole page.
Ajax contains various methods those are:
POST: This method is used for posting data to server side.
GET: This method is used to get value from server to client.
PUT: This method is used to update data value at server side.
DELETE: This method is used to delete data value at server side.
For working with Ajax we just requires jQuery library.
Bootstrap is the most popular HTML, CSS, and JS framework for developing responsive, mobile first projects on the web. With new technology coming in every new day we have something new called as Bootstrap which is used for making responsive UI. If we implement applications with normal css we can access application only from Desktop PC with perfect UI design but if we try to access same application from Tabs, mobile and various deceives our site design will get change completely. In case If we develop application with bootstrap framework CSS our site design will be responsive based on the device we used.
Bootstrap is already available in Visual studio 2013 and in case if you want to download directly bootstrap is open source Framework from Twitter and released as an open source product in August 2011 on GitHub.
Download Bootstrap from following link: - http://getbootstrap.com/