Sand filter and sand filter tank

We often hear to the sand filter and sand filter tank, so what's the difference between them.
sand filter, also known as quartz sand filter or filter is a set of a complete set of equipment, including filter tanks, quartz sand, backwashing and positive wash pipe valves and water needed for booster pump, electric cabinet, sand filter also points of shallow sand filter and general filter speed of the sand filter. Sand filter with sand filter of manual and automatic sand filter, and sand filter tank is just ordinary filter tanks, including the top and bottom water distribution device, manhole, discharging mouth, leg, and so on the necessary parts of the filter tank. Sand filter tank is 304 stainless steel material, stainless steel 316 l material and carbon steel material, as well as glass fiber reinforced plastic material. Each material sand filter tank is not the same price, relatively cheaper glass steel and carbon steel material, stainless steel sand filter to be expensive, because the price of raw materials, manufacturing process is different.