I'm very new to ajax and jquery. i'm trying to understand below examples.http://www.w3schools.com/ajax/tryit.asp?filename=tryajax_firsthttp://www.codeproject.com/Articles/17203/Using-jQuery-for-AJAX-in-ASP-NETfirst examples does not use jquery and it uses XMLHttpRequest for sending and receiving data asynchronously but in the second example it uses jquery and i need to know why the XMLHttpRequest object is not in use?