The document discusses social networks and social network analysis. It defines a social network as connections between individuals or organizations through various social relationships. It then discusses how social network analysis can be applied to map and measure relationships between people, groups, and other entities. Key aspects of social network analysis include degree centrality, betweenness centrality, and closeness centrality. The document provides examples of how social network analysis has been applied and discusses how technologies like LinkedIn and future modeling could further social network analysis.