The book provides an examination of how fog security is changing the information technology industry and will continue to in the next decade. The authors first discuss how fog enables key applications in wireless 5G, the Internet of Things, and big data. The book then presents an overview of fog/edge computing, focusing on its relationship with cloud technology, Internet of Things and the future with the use of secure 5G/6G communication. The book also presents a comprehensive overview of liabilities in fog/edge computing within multi-level architectures and the intelligent management. The last part of the book reviews applications of fog/edge computing in smart cities, including in Industrial IoT, edge-based augmented reality, data streaming, and blockchain-based.