How can you use absolute paths to include files in PHP?

When including files in PHP, using absolute paths can ensure that the correct file is always included, regardless of the current working directory. Absolute paths specify the full path to the file on the server, starting from the root directory. This can be achieved by using the $_SERVER['DOCUMENT_ROOT'] superglobal variable to get the root directory path and concatenating it with the relative path to the file.

<?php
include $_SERVER['DOCUMENT_ROOT'] . '/path/to/file.php';
?>