Asynchronous JavaScript and XML, or Ajax, is a web development technique for creating interactive web applications using a combination of:

• HTML (or XHTML) and CSS for presenting information
• The Document Object Model manipulated through JavaScript to dynamically display and interact with the information presented
• The XMLHttpRequest object to exchange data asynchronously with the web server. (XML is commonly used, although any format will work, including preformatted HTML, plain text, JSON and even EBML)