Where can one find reliable resources for learning about PHP headers and content types?

When working with PHP headers and content types, it is important to ensure that the correct headers are set to specify the content type of the response being sent from the server. This is crucial for proper rendering of the content in the browser. Reliable resources for learning about PHP headers and content types include the PHP documentation, online tutorials, and forums dedicated to PHP programming.

<?php
// Set the content type to text/html
header('Content-Type: text/html');

// Your PHP code here
?>