Cycling/Exercise bike difference?

[Rob G]

Is there any difference in how each of these affect muscles or which muscles they affect? I was under the assumption it was the same for both.
I understand that with real cycling the uphill/downhill roads you may face will react differently with your body, but isn't this the same as just tightening the pedals on an exercise bike?

[melissa]

with real cycling you will get a more varied workout because, unless you cycle on a track, the road will change, uphill, down hill etc. This means you can burn more calories. An exercise bike is just the same repetitive motion.