Disruptive innovation, a category named by my Harvard Business School colleague Clay Christensen, requires a new business model but not necessarily a technological breakthrough. For that reason, it also challenges, or disrupts, the business models of other companies. For example, Google’s Android operating system for mobile devices potentially disrupts companies like Apple and Microsoft, not because of any large technical difference but because of its business model: Android is given away free; the operating systems of Apple and Microsoft are not.