>>/9159/
Yes, there are several models.

The default mpm for apache is prefork.
https://httpd.apache.org/docs/2.4/mod/prefork.html

First line:
>  This Multi-Processing Module (MPM) implements a non-threaded, pre-forking web server. 

Also, later onwards:
>  How it Works

>  A single control process is responsible for launching child processes which listen for connections and serve them when they arrive.

Wow... it's almost like I know about what I say.