This article will guide you on how PHP FastCGI Process Manager (PHP-FPM) daemon works. PHP-FPM Code and FileSystem Layout for EasyApache allows the website to handle loads.
As PHP-FPM receives a proxied connection, a free PHP-FPM worker accepts the web server's request. PHP-FPM then compiles and executes the PHP script, sending the output back to the web server. Each PHP user can have its own separate pool of worker processes for handling PHP requests.
FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation with some additional features (mostly) useful for heavy-loaded sites. These features include:
i. Ability to start workers with different uid/gid/chroot/environment.
ii. listening on different ports and using different php. ini (replaces safe_mode).