What is AJAX good for?

So far the thing开发者_开发问答s I can do with AJAX are handle requests and reload content.

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What Else?

It also helps you maintaining sessions for your customer. by sending every interval requests.

No, that's it - but it's all about the consequence that results from this:

It allows you to keep a part of the application state on the client side (with traditional web pages, the entire browser DOM is reset for every request).