Cast iron is the traditional material used to manufacture a stove. Cast iron stoves take a longer time to heat up and hold their heat, so giving a high heat output for a longer time. The most controllable stoves are often cast iron.
Steel stoves often heat up quickly to give prompt heat to a room and because steel bodied stoves are typically more airtight, they offer more sensitive burn speed control. The door seal is sometimes not as tight as a cast iron stove, but due to the elastic nature of steel it is very durable and resistant to damage.