ajax cannot work independently. it is used in combination with other technologies to create interactive webpages.

javascript

• loosely typed scripting language.
• javascript function is called when an event occurs in a page.
• glue for the whole ajax operation.

dom

• api for accessing and manipulating structured documents.
• represents the structure of xml and html documents.

css

• allows for a clear separation of the presentation style from the content and may be changed programmatically by javascript

xmlhttprequest

• javascript object that performs asynchronous interaction with the server.