Social Network Analysis

Social networks are at the heart of big data, with their huge quantities of data of all kinds, text, images, video, and audio. Graphs are used to represent social networks in particular and all networks in general. They are sets of vertices linked together by edges. In many applications of social networks, it is important to identify the most influential individuals. In a graph, the importance of a vertex can be expressed in several ways, the main ones being the degree centrality, the closeness centrality, the betweenness centrality, and prestige. A clique is a graph in which all vertices are connected and a quasi‐clique is a group of vertices that are highly connected. A community is a subgraph that is both a quasi‐clique and a quasi‐connected component. The business model of social networks is the provision of free services in exchange for personal data.