AJAX stands for Asynchronous JavaScript And XML
The meaning: Web clients can send or receive data to/from the server without requesting an entire page - instead, clients can just request or send an arbitrary amount of data
In front-end development, AJAX is often used to make API requests that will fetch data from another service without having to refresh the web page
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Update a web page without reloading the page
Request data from a server - after the page has loaded
Receive data from a server - after the page has loaded
Send data to a server - in the background