The neutron is an unstable nucleon outside the atomic nucleus; its mass is approximately 0.0014 times higher than the proton's mass and it plays an essential role in the atomic nucleus's stability. The neutron does not have an electric charge and interacts with matter causing numerous reactions. The above properties make the neutron essential in several areas. In nuclear power production, for instance, the neutron combined with the moderator plays a critical role. This book is a collection of works related to the neutron and its applications. Each chapter of this book's content is self-contained and is derived from the experience and research carried out by the authors. The book describes each aspect of neutrons ranging from their essential characteristics to their applications. Chapters of this book concern topics including the description of neutron characteristics, the challenge of neutron dosimetry, the ambient dose equivalent due to cosmic neutrons, the use of neutrons as an analytical tool through neutron activation analysis, the absorbed dose response of natural minerals which also have thermoluminescent features, and the use of neutrons in medicine to treat cancer and rheumatoid arthritis. The book also discusses topics such as neutron attenuation by super-alloys, neutron production in radiotherapy with electrons, the use of neutrons to detect explosives, and cloud computing technology for neutron dosimetry and spectrometry. This book would be handy for scientists, engineers, researchers, students, and practitioners in neutron studies and applications.