This book describes the phenomenon of the smart city in all its facets through sociological lenses. What is a smart city? What social challenges is it addressing? What are its limits and what are its potentialities? The concept of the smart city is still somewhat unclear, although the smart city project is currently at the forefront of society. Through a precise analysis of the concept of "smart", the book provides a holistic definition of what constitutes a smart city. It will guide readers who want to analyse and describe the smart city, not only in the sociological field, but also in the technical-scientific field, and for those who want to explore its limits, its potentialities and its future developments.