#OrderTypes101 OCO (One Cancels Other) order:

An order that contains two orders, and when one of them is executed, the other is automatically canceled.

Buy-stop and Sell-stop orders:

Orders that use trigger prices to activate buy and sell trades, respectively.

Stop-limit order:

An order that becomes active when a certain price level is reached. After activation, it becomes a limit order.

Stop-market order:

An order that becomes active when a certain price level (trigger price) is reached. After activation, it turns into a market order.