What's the point of Octoprint as a Docker container?

Having ordered my first 3D printer, I am giddy and preparing various things.

I have installed Octoprint on my home server as a Docker container, but when running it, it seems that it wants to have a serial connection to a printer. Octoprint expects to be running on a Raspberry that is connected via its serial interface.

What am I missing?

The printer I ordered (Prusa Mini) comes with a wifi dongle, so I guess there will be a way to reach it over the network. But that does not automagically mean Octoprint can work with it.