Some of the new refrigerators that come out have a water dispenser. It usually is connected to tap water which is more convenient rather than always filling a reservoir or putting water bottles inside the fridge. But there may be some concerns about tap water. To make sure the water is clean, they put a refrigerator filter to make sure that the water it dispenses or the ice that is chilled is pure and clean. It also tastes better than having no filter at all.