Porter described an industry as having multiple "segments" that can be targeted by a firm. The breadth of its targeting refers to the "competitive scope" of the business. Porter defined two types of "competitive advantage": lower cost or differentiation relative to its rivals. Achieving competitive advantage results from a firm's ability to cope with the five forces better than its rivals. Porter wrote: "Achieving competitive advantage requires a firm to make a choice...about the type of competitive advantage it seeks to attain and the scope within which it will attain it." He also wrote: "The two basic types of competitive advantage and lower cost combined with the scope of activities for which a firm seeks to achieve them lead to three "generic strategies" for achieving above average performance in an industry: cost leadership, differentiation and focus. The focus strategy has two variants, cost focus and differentiation focus." In general: