The Internet of things (Io T) is a network of connected physical objects or things that are working along with sensors, wireless transceiver modules, processors, and software required for connecting, processing, and exchanging data among the other devices over the Internet. These objects or things are devices ranging from simple handheld devices to complex industrial heavy machines. A thing in Io T can be any living or non-living object that can be provided capabilities to sense, process, and exchange data over a network. The Io T provides people with the ability to handle their household works to industrial tasks smartly and efficiently without the intervention of another human. The Io T provides smart devices for home automation as well as business solutions for delivering insights into everything from real-time monitoring of working systems to supply chain and logistics operations. The Io T has become one of the most prominent technological inventions of the 21st century.Due to the versatility of Io T devices, there are numerous real-world applications of the Io T in various domains such as smart home, smart city, health care, agriculture, industry, and transportation. The Io T has emerged as a paradigm-shifting technology that is influencing various industries. Many companies, governments, and civic bodies are shifting to Io T applications to improve their works and to become more efficient. The world is slowly transforming toward a "smart world" with smart devices. As a consequence, it shows many new opportunities coming up in the near "smart" future for Io T professionals. Therefore, there is a need to keep track of advancements related to Io T applications and further investigate several research challenges related to the applicability of Io T in different domains to make it more adaptable for practical and industrial use. With this goal, this book provides the most recent and prominent applications of Io T in different domains as well as issues and challenges in developing Io T applications for various new domains.