out-of-order execution (OoOE)
Out-of-order execution (OoOE) is an approach to processing that allows instructions for high-performance microprocessors to begin execution as soon as their operands are ready. Although instructions are issued in-order, they can proceed out-of- order with respect to each other. The goal of OoO processing is to allow the processor to avoid a class of stalls that occur when the data needed to perform an operation are unavailable.