How can Apache's .htaccess file be used to redirect requests to a PHP script and maintain URL concealment?

To redirect requests to a PHP script and maintain URL concealment using Apache's .htaccess file, you can use the RewriteRule directive to rewrite the URL internally without changing the URL in the browser's address bar. This allows you to keep the original URL hidden from the user while processing the request through a PHP script. ```apache RewriteEngine On RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ index.php?url=$1 [QSA,L] ```