Micro Pump regulator

I was wondering if someone could tell me how to regulate a micro pump so when there is fluid used or the pressure drops, the pump would come on. When the pressure is back to a predetermined pressure the pump would turn off. Is there a special name for this type of pump or do I need something to go with it to regulate this. This would only be very low pressure.

I guess the easy comparison would be like in a old camper or motor home that when you turn on the cold water facet the pump engages, when you close the facet the pump shuts off.

Just a pressure switch. The RV/camper pumps are all done by Shur-Flow, they use a pressure diaphragm which pushes against a mechanical switch.