## A Collection of Technologies

So we see Ajax is really a collection of technologies that are working together to send and receive data to and from the web server based on user actions, and to format and display this data to the user.

Some of the key technologies involved are:

- HTML
- CSS
- JavaScript
  - DOM (Document Object Model)
    The DOM is used to format the content and manipulate the content of the page that is displayed in the browser.
  - XHR object (XHR = XMLHttpRequestObject)
    This is the object in JavaScript that constructs and sends the request back to the server
- Data formats
  - JSON (JavaScript Object Notation)