1
Browser. Asks for laravel.test. Any directory under a parked path answers to its own name, subdomains included.
2
DnsMasq. Resolves every *.test to 127.0.0.1. Config under ~/.config/valet/dnsmasq.d/; ping foobar.test proves it.
3
Nginx, started at boot, listening on 127.0.0.1 only. valet secure adds TLS and HTTP/2 for one site.
4
Driver. A PHP class with serves, isStaticFile and frontControllerPath. Laravel, WordPress and others are built in.
5
PHP-FPM, over ~/.config/valet/valet.sock. One global PHP, or valet isolate php@8.2 for a single site.
6
Your app. public/index.php of the parked directory. Nothing is copied; the site is served from where it sits.