The Five COmpetition start with the notion that competition is often looked at too narrowly by managers, and the 5 forces says that, you are competing with your direct competitors, but you are also in a fight for profits with a broader extended set of competitors, customers who have bargaining powers, suppliers who can have bargaining power, new entrants who might come in and kind of grab a piece of the action, and substitute products or services that essentially place a constraint or a cap on your profitability and growth
So the 5 forces is kind of a holistic way of looking at any industry and understanding the structural underlying drivers of profit ability and competence.