4.228 is a critical introduction to the theories and forms of representation of contemporary urbanism. The course is structured through weekly analyses of notions, projects and elements that can allow us to intervene in contemporary processes of spatial production. It will begin with a session dedicated to the concept of urbanization—which we will read as a sociospatial process of territorial structuring ultimately shaping the world at large—and then we will mobilize this planetary framework to investigate how the urban process has radically transformed previous spatial concepts and challenged our disciplinary means of praxis, thus creating new spaces for action, but also new disciplinary responsibilities and uncertainties. With that purpose, instead of relying on an inherited, static vocabulary of spatial levels, the seminar opts for discussing a set of categories that can help us to portray the urban as a multilayered, dynamic and transcalar phenomenon, affecting environments and artifacts, humans and non-humans alike.