This document discusses the importance and benefits of rapid prototyping. It notes that ideas are cheap to generate but building them out requires effort. Rapid prototyping allows one to test an idea with minimum effort through manual, low, or high fidelity prototypes before investing in a real product. Different prototyping methods and tools are presented, as well as the importance of testing prototypes with customers through activities like guerrilla testing. The overall goal of prototyping is to validate ideas and receive feedback to iterate on a concept before significant resources are spent on development.