Many phenomena around us follow a network structure. From the internet and social relationships to the spread of diseases, biological systems, and financial markets, networks provide a powerful way to analyze complex systems. In this talk, we will introduce fundamental concepts of network science and key models such as random networks, small-world networks, and scale-free networks. We will also explore various analytical approaches to understanding networks and discuss real-world examples, including how diseases spread, how information flows, and how social structures are formed. Finally, we will reflect on the future of network research and its potential impact on different fields.