The Internet of Things (IoT) has revolutionized connectivity by linking physical devices, systems, and services through intelligent networks. Its integration into industries and daily life has transformed efficiency, automation, and data management. Handbook of Internet of Things provides a detailed exploration of IoT architecture, communication protocols, and application domains. The book discusses sensor networks, cloud integration, edge computing, and security challenges. It also examines industrial IoT, smart cities, and healthcare innovations. By combining technical foundations with practical insights, it serves as an essential reference for engineers, developers, and researchers working to design and manage connected, intelligent ecosystems.