What is PHP-FPM, and what role does it play in serving PHP applications through a web server like Nginx?

PHP-FPM, or FastCGI Process Manager, is a PHP implementation that manages a pool of worker processes ready to handle incoming PHP requests, working alongside a web server like Nginx which handles serving static files and forwards PHP specific requests to PHP-FPM for actual processing, and this separation of concerns generally provides better performance and more flexible process management compared to older, simpler PHP execution models.

# Nginx configuration snippet
location ~ \.php$ {
    fastcgi_pass unix:/run/php/php8.2-fpm.sock;
    fastcgi_index index.php;
}