The chapter discusses the emerging field of network science, which has seen significant interdisciplinary interest and progress in recent years. It reviews the major findings and models in this field, including the small-world networks and scale-free networks. Small-world networks, characterized by high clustering and short average path lengths, were first introduced by Watts and Strogatz, who demonstrated that real-world networks often exhibit these properties. Scale-free networks, with a degree distribution following a power law, were later identified in various real-world networks. The chapter also explores the implications of network structure on collective dynamics, such as disease spreading and information exchange. It highlights the importance of distinguishing between symbolic and interactive networks when interpreting empirical data and discusses the challenges in understanding the relationship between network structure and collective behavior. The chapter concludes by emphasizing the need for further research to fully understand the dynamics of networked systems.The chapter discusses the emerging field of network science, which has seen significant interdisciplinary interest and progress in recent years. It reviews the major findings and models in this field, including the small-world networks and scale-free networks. Small-world networks, characterized by high clustering and short average path lengths, were first introduced by Watts and Strogatz, who demonstrated that real-world networks often exhibit these properties. Scale-free networks, with a degree distribution following a power law, were later identified in various real-world networks. The chapter also explores the implications of network structure on collective dynamics, such as disease spreading and information exchange. It highlights the importance of distinguishing between symbolic and interactive networks when interpreting empirical data and discusses the challenges in understanding the relationship between network structure and collective behavior. The chapter concludes by emphasizing the need for further research to fully understand the dynamics of networked systems.