This chapter describes the Internet of Things (IoT). Today more devices are internet-enabled than there are people in the world. They start by outlining the history of the IoT, and move on to its industrial counterpart, the Industrial Internet of Things. The chapter summarizes the innumerable applications of this innovation, notably in the realm of geospatial technologies, the challenges involved in its use, and note future research directions. In an age of ubiquitous, mobile, and invisible computing, the IoT may well define the future of the internet.