This book presents and compares different educational environments in contemporary Portugal: private schools attended by the elite and poor public schools located in poor neighbourhoods. Based on two different sociological projects but following similar frameworks, our aim is to discuss organizational strategies and socialization processes within a traditionally centralized and unified educational system, allegedly ruled by the principle of equal opportunities for all. Theoretically, concepts as socialization and educational system are discussed, both in global terms and in the context of contemporary changes in Portuguese society. Empirically, the field research in four schools is sketched. This comparison has found some convergence trends, but also many contrasts between socialization in both contexts, challenging key values of the educational systems, as integration and equity.