The Knowledge Grid is an intelligent and sustainable interaction environment that consists of autonomous individuals, self-organized semantic communities, adaptive networking mechanisms, evolving semantic link networks keeping meaningful connection between individuals, flows for dynamic resource sharing, and mechanisms supporting effective resource management and providing appropriate knowledge services for learning, innovation, teamwork, problem solving, and decision making. This book presents its methodology, theory, models and applications systematically for the first time.Its second edition fulfils the ideal of the Knowledge Grid by includingmany new contents, including: (1) The insight of cyber-physical society; (2) The systematic method of semantic link network that supports uncertainty management, discovery of semantic links and semantic communities, autonomous semantic data model, and cyber-physical-socio semantic link network; (3) Semantic peer-to-peer infrastructures for efficient knowledge sharing; (4) A new centrality measure of network; and (5) The Energy-Knowledge Grid. This new edition will undoubtedly provide inspiring materials for researchers, academics, practitioners and students.