The chapter deals with the development of smart cities as a model of digital innovation for urban development. The main factors that characterise smart cities are analysed, including innovation, environmental sustainability, intelligent mobility, human and social capital, and participatory governance. The integration of the Internet of Things (IoT) is identified as a crucial element for connecting the physical and virtual world, optimising urban resources and improving public services. The role of low power wide area networks (LPWAN) in supporting IoT applications, essential for the creation of smart cities, is also explored. Finally, the chapter examines the main application areas of smart cities, including intelligent buildings, energy management, environmental monitoring, urban mobility and territorial security, underlining how these technologies can improve the quality of life of citizens and promote sustainability. It is therefore analysed how the A2A group, a leading company in digital transformation and sustainability, implements technological solutions for the purpose of creating smart cities.