AJAX allows every element within a Web interface to be individually and quickly updated without affecting the rest of the interface. This, of course, is not what most Web users are accustomed to. Initiating an action within most Web sites triggers the inevitable blank screen and page loading process. Though not very responsive, the full-page update makes it very clear to users that their action has resulted in a reaction and that a response will be available as soon as the page is refreshed. Because AJAX-based updates are very fast and incremental (often affecting only a small portion of the UI), users may not notice them -especially when they are used to seeing full-page rewrites.
