No worries, Hoop
(not really a Japan Sensei.. just pass on what I learn here as time goes on only had two years here so far so really only a beginner )

Actually the onsen are the places that have the hot baths (sometimes natural, sometimes not) whereas the ryokan are the traditional inns.

Sometimes the ryokan have onsen and sometimes the onsen have ryokan.. but not always.

Sometimes modern hotels and health places have onsen also...

Hope that helps

(thanks for posting.. always value your input )