This document provides an introduction to the Internet of Things (IoT). It discusses how IoT will connect trillions of sensors to computing systems and services, allowing everything from appliances to infrastructure to be networked. This will profoundly impact areas like education, business, science, and more. The document outlines some of the key challenges to IoT development, such as transitioning to IPv6 and developing common standards. It also summarizes several chapters that will educate the reader on IoT fundamentals and its potential to transform many aspects of life.