What does bounce do exactly?

Could someone explain in a few words?

Bounce: Play something and re-record it to a new file. In Ardour’s case to a new region in the region list.

So, that will give me a new midi file in case I bounce a midi region, and a new audio region when I bounce an audio region. If I want to “bounce” down a midi region into an audio region the only way to do this is to just record the audio out of the plugin into a new audio track?