OCO Order

One Cancels Other. An order placed so as to take advantage of price movement, which consists of both a Stop and a Limit price. Once one level is reached, one half of the order will be executed (either Stop or Limit) and the remaining order canceled (either Stop or Limit). This type of order would close your position if the market moved to either the stop rate or the limit rate, thereby closing your trade, and, at the same time, canceling the other entry order.
Example: If you have an open buy JPY position, which you bought at 104.00, and you want to set a limit and a stop order, you could place an OCO order. If your OCO limit rate was 103.5 and OCO stop rate was 104.50, once the market rate reaches 103.5, the original JPY position would be closed and the stop rate would be canceled.