Ajax stands for Asynchronous JavaScript And XML and it is not a programming language. It uses XML to transport data, but it is equally common to transport data as JSON text or plain text.

front end interview questions
It allows webpage to be updated asynchronously by exchanging data with a webserver behind the scenes. It means that it is can update parts of a webpage without reloading the whole page in website.
BY Best Interview Question ON 09 Dec 2020