It’s pretty much like Caddy vs. nginx: Language runtime, static asset serving, TLS, routing and so on bundled in a single package. That makes it very easy to deploy a container, for example.

Thinking of a typical PHP app, which exposes both dynamically routed endpoints and static asset. With a traditional setup, you’d let nginx handle all paths as static assets and fallback to the index.php file to serve the app. When you package that as a container, you’ll either have to use separate PHP-FPM and nginx containers, or run two processes in a single container. Both of which is not ideal. And it gets ever more complex with TLS, and so on.

Using unit or caddy, you can simplify this to a single container that achieves it all, easily.