Our smart cities and Digital Twin applications are integrated urban management solutions that include the components outlined in the International Smart City Roadmap, where we integrate our information and communication technologies. Smart cities aim to make infrastructure, transportation, energy and environmental management more effective by using technologies such as sensor networks, Internet of Things (IoT) and big data analytics. Smart Cities optimize traffic, parking and energy consumption through applications such as intelligent transportation systems and energy management. On the other hand, the Digital Twin concept enables real-time monitoring and analysis of urban planning, infrastructure management and industrial processes by creating virtual copies of real assets. Integration and security are critical to the success of these applications, as all the different systems in the city need to be brought together seamlessly and data security needs to be ensured. All these concepts are important technological approaches and solutions that aim to make cities more sustainable, efficient and resilient.