The aim of this course is to give an overview of the key ideas of network science from a social science perspective. The concept of networks has come to pervade modern society, as we routinely make use of online social networking services, as business gets organized into network forms, and as warfare increasingly targets a loose network of combatants. Network science is an emerging interdisciplinary field, which aims at explaining such complex phenomena, emerging from simple principles of making links. Sociological research on the invisible network infrastructures of global finance, the emergence of social movements, or the formation and operation of terrorist groups all demonstrated that a few critical links can lead to dramatic transformations. This course gives an overview of key research findings in these areas, and it also introduces key methods to record, analyze, and visualize network data. Students will be given access to diverse datasets for class purposes.