This document explains to you how to install Xdebug extension to your Web server and prepare it for work with PhpStorm.
Since PHP 5.3, you always need to use the zend_extension, and not 'zend_extension_ts', 'zend_extension_debug' or 'extension'.
Add the following lines to the 'Xdebug' section of your php.ini file:
xdebug.remote_host=<the host where PhpStorm is running>
xdebug.remote_port=<the port to which Xdebug tries to connect on the host where PhpStorm is running>
Note: The value of 'xdebug.remote_host' can be a host name or an IP address (e.g. localhost).
Note: The value of 'xdebug.remote_port' is usually 9000. It is default value in Xdebug and PhpStorm. Ensure that the specified port is opened on your client machine.