Important contributions have been made to our knowledge of squatters in sociology, anthropology, geography, political science, planning, and architecture. In addition, there is research led by international organizations, agencies, and NGOs. Squatting is the occupation of vacant land or buildings, without the consent of the owner. But squatting involves a wide range of activities, claims, goals, resources, locations, and relationships with authorities, and squatters can have many different profiles. A common response has been the creation of typologies. A central problem has been fragmentation of the approaches to the study of squatters. Interested in different dimensions, these literatures are separated by cleavages. Five main cleavages can be identified around which research is organized: North/South, urban/rural, survival tactics/social movements, buildings/lands, inhabitants/policies. Distinct approaches by scholars with different backgrounds and theoretical interests limit our ability to understand the phenomenon. This entry attempts to address the diversity of issues and debates around them.