The economic concept of networks refers to the structure of agents' interaction as well as to the economic property of positive externalities. This book describes the economics of networks from various perspectives among which are classical approaches, methods derived from physics, theory of evolutionary games, and experimental economics. These different views shed a new light on the behaviour and interaction of economic agents, on networks and on related phenomena: e.g., emergence of stable macro structures from micro interactions, standardisation, diffusion, preservation of diversity, role of heterogeneity, local learning, surplus creation and surplus allocation. The book presents the state of the art and offers a unique opportunity to understand specific networks phenomena through different theoretical and experimental approaches.