This book covers the entire syllabus for Module-4, namely the Internet of Things and Its Applications, in a clear and simple style. Each concept in the book is illustrated with practical examples, and the tested output of programs are also provided. The book elucidates both basic and advanced topics in “IoT.” The book presents a detailed discussion on the Internet of Things and Its Applications/Devices, Protocol, and Communication model. Also, comprehensive coverage of various aspects of IoT and Arduino concepts are done. Different topics such as Sensors, Actuators, Microcontrollers, Security, and Future of IoT Ecosystem are explained in very easy to understand language. In addition, Personality development is covered to enhance skills set towards better personality development and maintain a positive outlook in life.Also, many solved, and unsolved examples are provided at the end of each chapter. An effort is made to explain all the topics in the layman’s language with the large number of illustrations and examples.