PHP-FPM (FastCGI Process Manager) is an alternative to FastCGI implementation of PHP with some additional features for sites with high traffic. The main advantage of using PHP-FPM is that it uses a considerable amount of less memory and CPU as compared with any other methods of running PHP. It transformed PHP to a background process while providing a CLI script for managing PHP request.
—Meghna Gangwar (August 4, 2022) How to Configure PHP-FPM with NGINX