What are the limitations of PHP in controlling browser settings for page loading?

PHP has limitations in directly controlling browser settings for page loading, as it is a server-side language and does not have direct control over client-side operations. However, you can use PHP to send headers that can instruct the browser on how to handle the page loading process. One common approach is to use PHP to set caching headers, which can help improve page loading speed by instructing the browser to cache certain resources.

// Set caching headers to control browser caching behavior
header("Cache-Control: no-cache, must-revalidate"); // HTTP 1.1
header("Pragma: no-cache"); // HTTP 1.0
header("Expires: 0"); // Proxies