A PHP info file displays information about your PHP installation that can be useful to troubleshoot your Magento installation.
To create the file, open up your favorite text editor and enter the following:
<?php phpinfo(); ?>
Save this file with a .php extension, like phpinfo.php, and upload it to a public location in your web hosting account, such as the web root our public_html directory.
You can now view the output of thise file by browsing to the location, e.g.: http://www.example.com/phpinfo.php
You will now be able to see information about your PHP environment that will allow you and others to troubleshoot your installation.
After you’re done with the file, you can safely delete it from the server.