What is the difference between a turbo and supercharger?

Both use rotation (in the form of a propeller, impeller, or otherwise) to force air through it. The difference between superchargers and turbochargers is that a supercharger is belt driven (and thus immediately gets up to speed the moment the throttle is applied) and a turbocharger gets up to speed by a turbine, fed with exhaust gases. This means that it has a delay between applying the throttle and actually getting the pressure of the turbo. Simply put, superchargers give more power immediately, but drop off as the revs climb. A turbocharger needs to "spool up" first, but will have more power once it does, as it generally creates far higher pressure. This is because it spins faster.