This document discusses the minimum viable product (MVP) concept and prototyping techniques. It defines an MVP as the version of a new product that allows a team to collect the maximum amount of validated learning about customers with the least effort. The document encourages focusing on the 20% of functionality that will be used 80% of the time and doing many iterations and pivots based on customer testing. It then describes various prototyping techniques like storyboards, physical prototypes, role playing, and split testing that can be used to test MVPs with customers and gather feedback to refine products.