How does setting the correct character encoding in the HTTP header and PHP file impact the handling of special characters in PHP scripts?

Setting the correct character encoding in both the HTTP header and PHP file ensures that special characters are handled properly in PHP scripts. This is important for displaying, processing, and storing text data that includes special characters like accents, emojis, or symbols. By specifying the character encoding, PHP will interpret and output text correctly, preventing issues such as garbled text or encoding errors.

header('Content-Type: text/html; charset=utf-8');
mb_internal_encoding('UTF-8');