If you need to move water in a pond, whether it is for a fountain, a waterfall or a filter you will need a pump.
As all these functions require different pump characteristics it is necessary to have pumps with different characteristics.
Fountain Pumps need to be stable and must be able to operate efficiently for long periods without the need for regular maintenance.
However they have to pump semi clean water to avoid blocking the fountain jet.
Waterfall pumps- need to be able to pump large volumes of water efficiently. This water however does not need to be free of solids.
Filter Pumps- need to be able to operate for long periods of time without blocking, they also need to be able to pass solids to the filter to enable them to be removed from the pond. As they are part of the life support system for the pond they need to be very reliable.