This document provides an overview of the Internet of Things (IoT). It discusses why IoT is important, what IoT is, and how to build IoT solutions. Key points include: IoT is expected to connect 20-50 billion devices by 2020; IoT takes advantage of technologies like sensors, networking, cloud computing and APIs; common IoT components include devices, networks, middleware platforms and the cloud; and popular protocols for IoT include MQTT, CoAP, Z-Wave and LoRa for networking, and TR-069, OMA-DM and OSGi for device management. The document also reviews open source and commercial IoT platforms and provides guidelines for designing IoT systems.