Game theorists might define a strategy as an approach to optimal decision-making while you are surrounded by other actors whose actions interact with yours. Chess strategies are a good example.

The author of Certain to Win, Chet Richards, takes a different approach. He defines strategy as "a scheme for creating and managing plans." It is a means to generate, act upon, and discard plans. Strategy is how you "plan to plan." OODA loops are a good example of this approach.