What are the differences between using Include and IFrame for optimizing website content in PHP?

When optimizing website content in PHP, using the include function is typically preferred over using iframes. Include allows you to dynamically insert content from other PHP files into your current file, which helps maintain a consistent design and structure across your website. On the other hand, iframes can sometimes cause issues with SEO, page load times, and responsiveness.

<?php
// Using include to optimize website content
include('header.php');
include('content.php');
include('footer.php');
?>