Data-driven cyber physical systems (DDCPS) are cutting-edge digital systems that revolutionize the way we interact with and integrate cyber space and the physical world. DDCPS consist of a sophisticated blend of computation, communication, control, and physical elements, all seamlessly woven together in a highly integrated framework. In this section, we begin with giving separate definitions of CPS and DDCPS from different perspectives. We then introduce the characteristics of DDCPS which include networked communication, scalability, heterogeneity, interdisciplinary, real-time processing and real-time decision-making. Next, components of DDCPS containing sensing parts, computational parts, communication parts and control parts are described. From theory to reality, we list some of the applications of DDCPS in different fields. Finally, the challenges that DDCPS will face in the future in data storage, integration, communication, cyber security and system stability are discussed.