AJAX stands for Asynchronous JavaScript and XML. It is a technique used in web development to create interactive and dynamic web applications. AJAX allows parts of a web page to be updated asynchronously without the need to reload the entire page. Traditionally when a user interacts with a web page the browser sends a request to the server and waits for a response. With AJAX however the interaction can happen in the background without disrupting the user experience. It allows the browser to make requests to the server receive data and update parts of the web page without reloading the entire page. AJAX uses a combination of technologies including JavaScript XML (although nowadays JSON is more commonly used) and the XMLHttpRequest object. It allows for seamless and interactive user experiences such as auto-complete search fields real-time updates and dynamic content loading. Overall AJAX enables web applications to be more responsive and efficient by reducing the need for full page reloads and improving the user experience.