php-fpm – PHP FastCGI Process Manager ’PHP-FPM’. By default, php-fpm will respond to CGI requests listening on localhost http port 9000. Therefore php-fpm expects your webserver to forward all requests for ’.php’ files to port 9000 and you should edit your webserver configuration file appropriately.
Nginx (pronounced engine-x) is a free, open-source, high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server. The nginx project started with a strong focus on high concurrency, high performance and low memory usage. For the detail about nginx, click here