How to install PHP-FPM on Ubuntu
By default Nginx is not capable of processing dynamic web pages with PHP so it requires the use of specific additional plugins for this purpose. One of these plugins is FPM (FastCGI Process Manager). FPM is an alternative PHP FastCGI implementation with some additional features (mostly) useful for heavy-loaded sites. It is the preferred method of processing PHP pages with Nginx and is faster than traditional CGI based methods.