The term Ajax has come to stand for a broad group of web technologies that can be used to apply a web application that communicates with a server in the backdrop, without interfering with the current state of the page. In the article that coined the term Ajax, Jesse James Garrett explains that it refers specifically to these technologies:
* XHTML and CSS for presentation
* the Document Object Model for dynamic display of and interaction with data
* XML and XSLT for the interchange and manipulation of data, respectively
* the XMLHttpRequest object for asynchronous communication
Since then, though, there have been a number of developments in the technology used in an Ajax application, and the definition of the term Ajax. In particular, it has been renowned that:
* The XMLHttpRequest object is not necessary for asynchronous announcement. It has been noted that IFrames are capable of the same consequence.