The web of life is an appropriate metaphor for living systems, whether they are ecological, anthropological, sociological, or some integrated combination, as most on earth now are. This phrase immediately forms the image of interactions and connectedness, both proximate and distal— a complex network of interacting parts, each playing off one another, providing constraints and opportunities for future behavior, where the whole is greater than the sum of the parts. The interconnected systems are viewed as networks because of the powerful exploratory advantage present when employing the tools of network analysis—graph theory, matrix algebra, and simulation modeling, etc. Networks are comprised of a set of objects with direct transaction among these objects. Although, the exchange is a discrete transfer, these transactions are viewed in total link direct and indirect parts together in an interconnected web, giving rise to the network structure. This chapter deals with that connectivity, provides an overview of systems approaches, introduces quantitative methods of ecological network analysis to investigate this connectivity, and concludes with some of the general insight that is gained from viewing ecosystems as networks.