By decoupling the data interchange layer from the presentation layer, Ajax allows for Web pages, and by extension Web applications, to change content dynamically without the need to reload the entire page. Ajax is not a single technology, but rather a group of technologies. Ajax is also not a new technology, or another different language, just existing technologies used in new ways. This process was inefficient, as reflected by the user experience: all page content disappeared, then the new page appeared. Each time the browser reloaded a page because of a partial change, all of the content had to be re-sent, even though only some of the information had changed. This increased interest in AJAX among web program developers. Since then, however, there have been a number of developments in the technologies used in an Ajax application, and in the definition of the term Ajax itself.