The concept of city evolves and adapts throughout history according to the dynamic world context. This is how currently investments and efforts are being focused on the development of smart cities. Although in these types of city's technology is a very important sector for improving the quality of life of citizens, it is more a means than an end. Among the components that are analyzed within this multidimensional concept are the circular economy and sustainable development, data, the idea of nocturnal cities, and governance and citizen participation. Nowadays, the most important decisions are taken at the local levels, since it is in the territory from where citizens know their most pressing needs and the most latent problems are located. Currently, cities are perhaps more relevant than nations themselves when it comes to responding to different problems. Therefore, smart cities emerge as a possible solution to these phenomena.