How can PHP be used to include external content on a website while maintaining its own links and properties?

When including external content on a website using PHP, it's important to ensure that the external content maintains its own links and properties without interfering with the rest of the website. One way to achieve this is by using PHP's `file_get_contents()` function to retrieve the external content and then using `echo` to output it onto the webpage. By doing this, the external content will be displayed on the website while still retaining its original links and properties.

<?php
$external_content = file_get_contents('https://www.externalwebsite.com');
echo $external_content;
?>