This document summarizes five innovations that have changed the startup world: 1. Business model generation introduced the business model canvas as a way to conceptualize startups. 2. Applying the scientific method means startups empirically test hypotheses about their business model rather than relying on business plans. 3. Customer discovery focuses startups on understanding customer problems before developing solutions to ensure they build something people want. 4. The lean startup methodology advocates for building minimum viable products to rapidly learn from customers and iterate business models. 5. Together, these innovations define startups as temporary organizations that search for scalable and repeatable business models through experimentation rather than execution based on plans alone.