Order status is a callback after you submit your order and it is identified by order id (programmer keeps track of order id).
It returns average fill price and last filled price, order status, quantity filled, remaining etc.
Programmer should keep track what was the initial order type, quantity, limit price etc. by using order id and then match received information against submitted order.
Very important: OrderStatus() may sent multiple messages with identical information for the same order id and this has to be handled by the program