The original gasoline station pumps were truly pumps. By working a hand lever on the side, the operator created a vacuum in the interior pumping unit and this, in turn, "pulled" product up from the storage tank below. Later, electric motors operated suction pumps, with the pumping unit located inside the dispensing device on the pump island.
In most modern gasoline stations, the actual pumping unit is not located in the dispenser. Rather, it is located in a remote position, within the storage tank.
The mechanism located on the pump island, therefore, is not really a pump. It is, rather, a dispenser. It contains a meter, electronic controls, a length of hose with a nozzle on the end, and quite probably a filtering element.
However, the piece of equipment on the pump island continues to be referred to by many people as a "pump" or a "gas pump." To accommodate this usage, it has become common, within the industry, to speak of the dispenser as a "dispensing pump," although "dispenser" is more accurate.