CGI interface is according to the HTTP protocol and the standard package for the right package, send IPCAM Web server on port and waiting for a reply on the link.
CGI interface according to the standard HTTP protocol packaged into the correct package, sent to the web server port IPCAM on, and wait for a response on that link.
CGI interface is packaged in accordance with the standard HTTP protocol into the correct package, the web server port on the IPCAM, and in the chain on the way to wait for a reply.