This book is about controlling motors using Arduinos (called Genuinos outside the United States). I start out with simple direct current (DC) motors, covering turning them on and off, controlling their speed, and reversing direction. I then get into more complicated motors. I discuss two types of stepper motors, a type of precision motor that can be used for detailed control of devices like 3D printers, CNC routers, robot arms, etc. I also discuss servo motors, which are useful for setting positions, and brushless motors, which are good for high speeds like you might need for drone or model plane propellers, fans, model boat propellers, high-speed model cars, and any other application that requires high speeds. This book covers both electronics and programming, so are be electronic schematics and Arduino sketches. I assume that the reader is already familiar with the basics of Arduinos, such as how to install the IDE and load sketches, so I do not go into details on topics like that. I use Arduino Uno as the basis for designs in this book, but other models will work for most of the applications discussed in this book. In the last chapter, I provide several links to locations where you can download the sketches in this book to save you the trouble of typing them.