jQuery is a JavaScript library (or framework), created by John Resig in 2006.jQuery is a fast and concise JavaScript Library that simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development. jQuery is designed to change the way that you write JavaScript.

jQuery validation plugin can be used for adding validations for your form in simple way.you need to add jquery plugin in your page and few javascript lines also there.

One of the biggest advantages that Ajax has in web pages is that it can access information on the server without having to reload the web page. This means that to retrieve or update one small piece of information only that information needs to be passed to and from the server instead of having to redownload the entire web page.There are two ways that Ajax can access the server.