AJAX allows asynchronous data loading without page reloads, while jQuery is a JavaScript library that simplifies AJAX calls and DOM manipulation. AJAX uses multiple technologies like CSS, HTML, DOM to provide new functionality by combining server-side processing with client-side changes. jQuery can access the front-end more easily without needing to understand the full AJAX procedure. AJAX can overload servers due to many connections, while jQuery is lighter weight and causes less overload.

1. AJAX Difference FAQs-1
1.Difference between AJAX and jQuery
S.No AJAX jQuery
1 AJAX is a powerful tool which JQuery is a light weight language
cannot use HTML since it is a that focuses the interaction in the
simple tool and it can not HTML elements.
reload the page after it is once
loaded.
2 AJAX is a combination of JQuery cannot provide a new
several technologies such as functionality by combining with
CSS, HTML, DOM and many other technologies.
more. In combination with
these technologies, AJAX
provides new functionalities.
3 AJAX should be accessed in a JQuery can be accessed through
proper procedure to retrieve front-end therefore JQuery does
data from the server. not require understanding of the
complete procedure to setup a
page.
4 Heavy usage of AJAX often There is no chance for overload of
leads to the server overload server while using JQuery since
due to more number of there is no such heavy usage in
connections created. JQuery.
2.Difference between AJAX and JavaScript
S.No AJAX JavaScript
1 AJAX allows the coder send JavaScript is a client side scripting
request data asynchronously in language that allows the creation of
order load new data without dynamic web pages by providing a
changing the web page. new level of interactivity.
2 AJAX supports the server side JavaScript provides support to the
scripting Language. client side scripting language.
3 AJAX can load the web page JavaScript cannot load the pages
after it is been loaded for the after it is once loaded.
first time.
4 AJAX does not install Trojan in JavaScript can install Trojan in the
the computer. computer.
3.Difference between AJAX and PHP
S.No AJAX PHP

2. 1 AJAX is an Asynchronous PHP is a Hypertext processor that
JavaScript XML that has a is a general scripting language
group of web technologies which produces dynamic web
which are interrelated. pages.
2 AJAX is not a stand alone PHP is a stand alone technology.
technology. AJAX is a group of
technology.
3 AJAX needs a specific platform PHP can run on any platform and
and operating system to run. operating system.
4 AJAX is difficult to develop on PHP is easy to develop on static
static pages. pages.
5 AJAX will only run if the PHP is highly vulnerable and does
browser supports JavaScript or not require much support.
XMLHttpRequest.
4.Difference between AJAX and DHTML
S.No AJAX DHTML
1 AJAX does not have the DHTML makes a Button glow or
feature of making the button pressed when the cursor is moved
glow when the cursor is moved over it.
over it.
2 AJAX can load a single link DHTML loads a fresh new page to
instead of loading the whole load a link.
new page.
3 AJAX saves the loading time. DHTML consumes more time than
AJAX takes in loading the page.
4 AJAX permits the browser to DHTML does change the element
request certain elements which on the screen depending on the
reduces the strain on the request from the user.
internet.
Reference: http://onlydifferencefaqs.blogspot.in/2012/08/ajax-difference-faqs-1.html