This document discusses prototyping as an approach to innovation. It emphasizes that prototyping allows testing ideas with real users before investing too many resources. The design thinking process is outlined, with prototyping occurring after defining the problem, ideating solutions, and before testing. Various prototyping platforms, tools, and techniques are listed, including paper mockups, sketching, InVision, storyboarding, role playing, and hardware. The overall message is that building quick, inexpensive prototypes early allows for learning and improving ideas through an iterative process.