What is the best practice for dynamically loading content in PHP without using frames?

When dynamically loading content in PHP without using frames, the best practice is to utilize AJAX (Asynchronous JavaScript and XML) to fetch and display content from the server without refreshing the entire page. This can be achieved by creating a PHP script that responds to AJAX requests and returns the desired content in a format such as JSON or HTML.

<?php
if(isset($_GET['content'])){
    $content = $_GET['content'];
    
    // Process the content request here
    
    echo $content; // Return the content
}
?>