Apache
In plain terms
A long-established, widely-used open-source web server.
Going deeper
The Apache HTTP Server serves web content reliably with a flexible module system, historically the most popular web server. It's battle-tested and configurable.
Under the hood
Process/thread-based model; .htaccess flexibility, though Nginx often outperforms it for high concurrency.
Examples
Web hosting, PHP sites, reverse proxying, legacy infrastructure.
Think of it like...
Like a veteran reliable workhorse that's been serving the web for decades.