Networks are everywhere, from the internet and social networks to the genetic networks that determine our biological existence. This groundbreaking textbook, fully illustrated in color, covers a wide range of topics from physics to computer science, engineering, economics, and social sciences, introducing network science to an interdisciplinary audience. From the origin of the six degrees of separation to explaining why networks are robust against random failures, the author explores how viruses like Ebola and H1N1 spread and why our friends have more friends than we do. With numerous real-world examples, this innovatively designed text clearly distinguishes between undergraduate and graduate-level materials. The mathematical formulas and derivations are included in the sections on advanced topics, allowing for use at various levels. Comprehensive online resources are also included.