NGINX and Apache — the two most popular. Choice affects speed and resources.
NGINX — light and fast
Event-driven. One worker handles thousands of connections. Low RAM. Static files 2-3x faster.
Apache — flexible
.htaccess per folder. Many modules. Beginner-friendly. Native PHP (mod_php).
Benchmark
10K connections, static HTML: NGINX 2.5s, Apache 7.8s. PHP dynamic similar (with FPM).
Combination
NGINX front (reverse proxy), Apache back. Speed + flexibility.