“Doing with images makes symbols.” —Alan Kay— Icons have become so familiar in everyday life that we hardly recognize them as anything special. They appear on computers, phones, tablets, smart devices, signs, analog planners, and even paper books. It is harder to find a place in modern society where icons are not used. Their simple, clean shapes make it easy to grasp intuitively what they mean, so they are used everywhere. The Secret of Icon Design covers the history and knowledge of icons and