How can PHP configuration settings like php_value and php_flag in .htaccess files be used to customize PHP behavior on a server?

PHP configuration settings like php_value and php_flag in .htaccess files can be used to customize PHP behavior on a server by overriding the default settings defined in the php.ini file. This can be useful for setting specific PHP directives for a particular directory or website without affecting the global PHP configuration. Example: ```apache # Enable display_errors for debugging php_flag display_errors on # Set maximum upload file size to 10MB php_value upload_max_filesize 10M ```