How can setting the "Content-Type: text/html; charset=utf-8" header in PHP code impact the handling of special characters in a web application?

Setting the "Content-Type: text/html; charset=utf-8" header in PHP code ensures that the web application correctly handles special characters like accents, emojis, and other non-ASCII characters. This header specifies that the content being served is in HTML format and encoded using the UTF-8 character set, which supports a wide range of characters. Without this header, special characters may not display correctly in the web application.

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