This chapter provides an overview of the Internet of Things (IoT), which refers to the interconnection of physical devices via the Internet. It discusses how IoT devices collect and share data to improve various processes, and can be used in several applications and sectors, including agriculture, energy, and healthcare. It also discusses the growth and adoption of IoT devices worldwide, along with associated challenges such as cybersecurity threats. Additionally, the text explores the convergence of IoT with other technologies like big data analytics and artificial intelligence. Finally, it outlines the structure of the book, which includes chapters on measuring IoT diffusion and case studies in the manufacturing and healthcare sectors.