necessitating innovative solutions for effective city management. Digital Twin Cities represent a dynamic tool that merges real- time data, advanced analytics, and visualization technologies to enhance urban planning, operations, and citizen engagement. These advanced digital ecosystems allow for comprehensive ° and predictive management of urban systems, providing valuable insights to city planners for decision-making and optimization. To tackle this complexity, the microlearning unit explores the concept of Digital Twin Cities as a „“System of Systems.” This methodology emphasizes integrating diverse urban components—like mobility, energy, environment—and synthesizing data from IoT sensors and public interactions into a coherent model. Doing so enables scenario testing, policy simulations, and a holistic approach to urban governance, making the city’s interconnected systems visible and manageable. The learning unit offers foundational knowledge on Digital Twin Cities, covering their role in urban management and their capabilities—such as simulation and real-time adaptation. It teaches through practical examples, comparing Digital Models, Digital Shadows, and Digital Twins, highlighting their technical layers. Moreover, the unit underscores the importance of real-time data and technological integration in building effective Local ° Digital Twins for urban resilience and innovation.