AJAX AJAX (Asynchronous JavaScript and XML) enables asynchronous data exchange between client's browser and web server. AJAX first appeared in Microsoft's browser IE in the late 1990s and quickly gained popularity. Today it is used almost on every website.

With AJAX developers can create modern, interactive user interfaces for the web that behave similarly to traditional desktop applications, that are so familiar to ordinary users. In simple terms AJAX allows web pages to update dynamically, without a page refresh, on user interaction or automatically.