AJAX technology is a way to update part of a page without completely reloading it. The technology is based on JavaScript, the HTTP protocol, and some server part, for example, PHP, NodeJS, or some other.
Currently, AJAX is handled through
fetch
. This is modern technology,
but doesn't work in older browsers. An
older technique is to use the
XMLHttpRequest
object. You
may still encounter this technology,
but you shouldn't delve into it too much.
To learn how AJAX works, you need a server. We will use our training server. Let's make an HTML file in the folder with the server, which we will open in the browser:
<!DOCTYPE html>
<html>
<head>
<title></title>
<script src="client.js" defer></script>
</head>
<body>
</body>
</html>
Link a JavaScript file to it:
alert('test');
Create the described files and check their operation in the browser.