How do I handle $_POST data with AJAX and PHP?

Handling $_POST data with AJAX involves sending data asynchronously from the client-side to the server-side without refreshing the page:

<form id="ajax-form">
    <input type="text" name="name">
    <input type="submit" value="Submit">
</form>
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<script>
$(document).ready(function() {
    $("#ajax-form").submit(function(event) {
        event.preventDefault();
        $.ajax({
            type: "POST",
            url: "ajax_handler.php",
            data: $(this).serialize(),
            success: function(response) {
                alert(response);
            }
        });
    });
});
</script>

In ajax_handler.php, handle the $_POST data:

<?php
if ($_SERVER["REQUEST_METHOD"] === "POST") {
    $name = $_POST["name"];
    echo "Received: " . htmlspecialchars($name);
}
?>

AJAX allows for smooth and interactive web applications by handling form submissions and other requests asynchronously.