Chapter 1. Differences and inequalities in contemporary cities: a spatial perspective -- Chapter 2. Understanding social exclusion -- Chapter 3. Keyword of social inequalities -- Chapter 4. Identities, exclusions and space -- Chapter 5. Participation in policies against urban social exclusion.The book explores social inclusion/exclusion from a socio-spatial perspective, highlighting the active role that space assumes in shaping social phenomena. Unlike similar books, it does not discuss exclusion and inclusion in particular geographical contexts, but instead explains these phenomena starting from the dense and complex set of relationships that links society and space. It particularly focuses on social differences and how the processes of exclusion and inclusion can produce a highly spatialized understanding of them, for example when particular groups of people are perceived as being out of place. At the same time, within the context of the different approaches that policies adopt to contrast the phenomena of social exclusion, it examines the role of participation as an instrument to promote bottom-up inclusion and cohesion processes.