Our growing dependence on networks has inspired a burst of research activity in the ﬁeld of network science. One focus of this research is to derive network models capable of explaining common structural characteristics of large real networks, such as the Internet, social networks, and many other complex networks. A particular goal is to understand how these characteristics affect the various processes that run on top of these networks, such as routing, information
sharing, data distribution, searching, and epidemics. Understanding the mechanisms that shape the structure and drive the evolution of real networks can also have important applications in designing more efﬁcient recommender and collaborative ﬁltering systems, and for predicting missing and future links—an important problem in many disciplines ….