No, PHP is not a server. PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML. Your web server (Apache) may be running one or more instances.
There is typically but one cgi handler so I would venture to guess the answer is no. You can always get on to your command line and run a "locate php5.cgi" or "whereis php5.cgi" command to see if others are anywhere on your system. And if so, you will also need to check the rest of your installation configuration to see where and which handler is handling your requests.