This paper deals with the comparative approach of the riots on one hand, and the student movement on the other. If both movements are based on young people mobilization, not all the dimensions which are important in explaining the riots (social classes, ethnicity and race, generation, space, family structure, gender) are so pertinent for the student movement. The riots were indeed the expression of relegation and a profound resentment that have bought into play both ethnoracial (youth from African immigrant backgrounds, directly concerned by discrimination and racism) and social dimensions (low-income backgrounds). But the riots did not develop simply on the basis of age and class, but rather that they bring into play the urban forms (segregation) of the increasing precariousness of part of the low-income population, particularly those of immigrant origin. Segregation reinforces the interaction and the association between these dimensions, and is a favourable condition for riots because of the concentration in the space of all the characteristics which are perceived as object of discrimination and because of the best control of territory. This shift, from inequalities to discrimination, is particularly visible in some specific social spheres like political representation, labor market, police, housing, and school.