Final answer:
Vane pumps are different from centrifugal pumps because they are essentially self-priming.
Step-by-step explanation:
The type of pumps that are different from centrifugal pumps in that they are essentially self-priming are called vane pumps.
Vane pumps are positive displacement pumps that use sliding vanes to create a vacuum and draw in fluid, allowing them to self-prime.
Unlike centrifugal pumps, which rely on the momentum of a rotating impeller to move fluid, vane pumps can start pumping immediately without the need for external priming or filling the pump with fluid.