Very simple. It’s a use of the XMLHttpRequest object available in the javascript namespace within a browser which allows you, asychronously, to submit HTTP requests and handle the response which, coupled with dynamic HTML techniques, allows you to submit and request data, and update a web page to reflect that data, without reloading the entire page, thereby providing a rich user experience more akin to the desktop paradigm than the usual HTTP fill-in-form-submit-process-get-new-page model.
It’s not a standard, which is why you need different initialisation code to create the object for different browsers, and the X part of it is strictly optional…
Very simple. It’s a use of the XMLHttpRequest object available in the javascript namespace within a browser which allows you, asychronously, to submit HTTP requests and handle the response which, coupled with dynamic HTML techniques, allows you to submit and request data, and update a web page to reflect that data, without reloading the entire page, thereby providing a rich user experience more akin to the desktop paradigm than the usual HTTP fill-in-form-submit-process-get-new-page model.
It’s not a standard, which is why you need different initialisation code to create the object for different browsers, and the X part of it is strictly optional…
Simple, eh?
From a developer’s point of view it is the dog’s kahoonas.