This book aims to present a theoretical study of the concept of collaboration during the Second World War, understood as social behaviour and actions within specific conditions of military occupation. It is based on the theories of social behaviour and action developed by Max Weber and the theory of action by Pierre Bourdieu. The book seeks to elucidate the concept of collaboration, the conditions fostering this phenomenon, and positions it within the broader context of cooperation under occupation. Through typological analysis, it provides a comprehensive assessment of various forms of collaboration, considering the motivations of the actors involved. Theoretical types of collaboration, as idealized constructions, will facilitate a deeper understanding of the motivations behind the social behaviour and actions of specific collaborating individuals.