Customer Development is a continuous process that helps you develop a product and business model based on customer feedback. Customer Development gives you a clear understanding of what your users and customers want, need and will pay for.
Pivot: A substantive change to one or more components of your business model.
Customer Discovery: Turning your initial assumptions about the market and customers into facts. Your product solves a problem or need for an identifiable group of users.
Customer Validation: Tests whether your business model is repeatable and scalable. The market is saleable and large enough that a viable business might be built. If not, you return to Customer Discovery.