In early 1990s most of Web sites were based on complete HTML pages. Every user action required that a complete page is to be loaded from the server. This process was not that efficient according to the user experience all page content disappeared then reappeared. Every time the browser reloads a page due to a partial change, all of the content is required to be resent, even though only some of the information is changed. This caused additional load on the server and required extra bandwidth.
In 1996, iframe tag was introduced by Internet Explorer to load or to fetch the content asynchronously.
In 1998, Microsoft Outlook Web team implemented the first component XMLHTTP by the client script.
In 1999, Microsoft used iframe technology to dynamically update the content and stock quotes on the default page for Internet Explorer and created the XMLHTTPActivex control in Internet Explorer 5 which was later adopted by Opera, Mozilla ,Safari. Microsoft adopted the XMLHttpRequest model as of Internet Explorer 7 though the ActiveX version is still supported by it. The utility of asynchronous Web technologies and background HTTP requests to the server remained obscure until it started appearing in full scale online applications.
Google made a wide deployment of cross browser Ajax with Gmail, standards compliant and Google Maps.
The term "Ajax" was stated publicly on 18 February 2005. It was introduced by Jesse James Garrett in an article named "Ajax: A New Approach to Web Applications" based on techniques which are used on Google pages.
The term Ajax represents a broad group of Web technologies that are used to implement a Web application that communicates with a server in the background, without interfering with the current state of the page.