A comprehensive book that takes readers on a captivating journey into the realm of intelligence and Open Source Intelligence (OSINT). With an emphasis on practical knowledge and real-world applications, this book covers a wide range of topics, from the fundamentals of intelligence to the intricacies of OSINT methodologies. In the early chapters, readers are introduced to the concept of intelligence, its historical evolution, and the various levels it encompasses. The book then delves into the intelligence cycle, warfight domains in a military context, and explores the 5th dimension of cyberspace and network-centric warfare. Additionally, it explores the emerging 6th dimension of cognitive warfare, highlighting its significance in modern intelligence operations. The book also examines different types of intelligence, including national security intelligence and criminal intelligence. Readers gain insights into the functions of criminal intelligence, the Europol EMPACT policy cycle, and the role of OSINT as a cross-disciplinary intelligence discipline.