At this point the Wizard has determined that we want to create a Sound configuration with a single engine Prop aircraft. The Source Sound Template shows us that we'll be using the default C182 sounds as a base, if we choose.
If we only wanted to create the directory structure and aircraft.cfg entries for a new configuration, we could click on the Create a Minimal sound config button. If we did, no actual wave files would be copied, and the sound.cfg file would only have a minimal set of entries.
You can experiment by changing the Number of Engines and Engine Type values, watching the Source Sound Template change values. For example, changing the Engine Type to Turboprop would change the Source Sound Template to Caravan (not really useful for a Prop engine!).