We first define and explain cyber physical systems (CPS) and their roles of complex systems in real-time optimization and decision-making. This chapter introduces the concept of data-driven cyber physical systems (DDCPS) and their significance in modern industries. Challenges of developing DDCPS are discussed, including data acquisition, analysis, modeling, and cybersecurity. The importance of artificial intelligence and big data techniques is also highlighted. This chapter provides an overview of the book, which covers key techniques such as data acquisition, analysis, and modeling, simulation, machine learning and AI, network and distributed computing, and cybersecurity. Case studies and real-world examples from various industries are featured, offering readers insights into the practical applications of CPS and DDCPS. We summarize by emphasizing the practical significance of DDCPS and providing readers with a framework for understanding the rest of the book’s content.