Modern conceptions of cities as smart and sustainable and their commonalities

The present work aims to determine the existence of commonalities between two modern conceptions of cities, i.e., smart and sustainable. To accomplish this, the authors carried out a systematic review of the most-cited scientific contributions chosen by the scholars proposing conceptualisation of the two topics, according to the H-index determined by Web of Science. The findings show that the most important contributions representing the antecedents with respect to the concepts of a smart city and a sustainable city can be classified into three groups: labelled as what, how and with, and describing the definitions, the role of technology, and the pillars (in the case of a smart city); the groups labelled as what, how and with depicts definitions, change and challenges, and key features (in the case of a sustainable city). Starting from the conception of a smart city as the evolution of a digital city, the smart city concept not only considers aspects related to technology and innovation but adds the human features of city life. The sustainable city concept can be understood as a new approach through the filter of a new philosophy; it is an equitable and balanced setting of goals in line with the principles of sustainable development. Both concepts cannot be thought of as contrasting; in fact, they share many commonalities. This is because the attention focused on social, environmental and economic issues has framed the debate over sustainability and converged in the definition of a smart city and—obviously—in the notion of a sustainable city. The main contribution of this paper is in considering the smart city as mainly setting the guidelines of a transforming city, while the sustainable city is mostly thought as an approach and a philosophy to modern cities.