When is it appropriate to use AJAX?

Question

When is it appropriate to use AJAX?
what are the pros and cons of using AJAX?

In response to my last question: some people seemed very adamant that I should only

Answer 1

Javascript should always just be an addition to the functionality of your website. You should be able to use and navigate the site without any Javascript involved. You can use Javascript as an addition to existing functionality, for example to avoid full-page reloads. This is an important factor for accessibility. Javascript should never be used as the only possibility to reach or complete a request on your site.

As AJAX makes use of Javascript, the same applies here.