This chapter defines strategy as a diagnosis that defines or explains a business challenge or opportunity, a decision or set of decisions for dealing with the challenge or opportunity, and a coherent set of actions to deliver on the decisions so as to create sustainable advantage and superior returns over rivals. In this chapter we also distinguish between three key levels of strategy: (1) corporate-level strategy, which is concerned with the selection of business areas in which the company should compete and with the development and coordination of that portfolio of businesses; (2) business-level strategy, which is about developing and sustaining a competitive advantage for a business delivering an identifiable set of products and/or services; (3) managerial-level strategic decision-making, which is concerned with identifying and dealing with a diverse range of immediate strategic challenges and opportunities confronting a business.