AJAX is designed to make web pages feel more responsive by exchanging small amounts of data with the server behind the scenes, so that the entire web page does not have to be reloaded each time the user requests a change. This is intended to increase the web page's interactivity, speed, and usability.
The fancy window affects of stuff moving, drag and drop, flashing, animation, etc is all merely a flashback to DHTML from the 90's, but repackaged and called AJAX. Most of it is all client (browser) side and doesn't depend on the server to browser communication to function. This is the primary reason I wrote my own AJAX code.
Create a login for your client and then have an edit link on all of the editable areas – they click on it and the content is replaced with a text area they can edit the content, they submit it and it is updated on the spot.