How does setting the HTTP header differ from using meta tags in HTML for specifying character encoding in PHP scripts, and why does it matter in handling special characters?

When specifying character encoding in PHP scripts, setting the HTTP header using the header() function differs from using meta tags in HTML. Setting the HTTP header in PHP ensures that the character encoding is correctly communicated to the browser before any content is sent, while using meta tags in HTML only affects the encoding of the HTML document itself. This difference matters when handling special characters because it ensures that the browser interprets the characters correctly.

<?php
header('Content-Type: text/html; charset=UTF-8');
?>