Many reports estimate that in 2024, the number of IoT devices exceeded 18 billion worldwide, with predictions to reach 40 billion by 2033. Despite primarily being consumer devices, a growing number of them will find use in industrial and enterprise applications. This shows the significance of IoT and how it will be shaping the future. However, to realize its full potential, we need to address its challenges and highlight its applications, advances, and related trends. Security and privacy represent some of the key challenges IoT adopters face. The growing number of IoT devices, the expansion of Industry 4.0 (and the emergence of Industry 5.0), and the significant increase in cybersecurity attacks exacerbate the severity of these issues. Considering how ensuring security and privacy are crucial for a successful adoption of IoT, this book dedicates several chapters to these areas. The book also presents some novel models that improve IoT environments. Similarly, the book presents several practical implementations that utilize IoT to demonstrate some of its real-world applications. Furthermore, the book presents several emerging technologies that enable the realization of advanced IoT environments. We see most IoT advances are taking place in three main areas: the integration of artificial intelligence/machine learning, network technologies, and hardware designs. Therefore, the book dedicates several chapters to these areas. Most chapters touch on the artificial intelligence/machine learning part, which emphasizes the significance of these technologies in today's and next-generation applications. The main objective of this book is to capture the state-of-the-art in IoT and cover some of its challenges, solutions, and emerging technologies. The book is peer-reviewed and serves as a reference for researchers, academics, practitioners, implementers, and graduate-level students.