Population transfer or resettlement is a type of mass migration that is often imposed by a state policy or international authority. Such mass migrations are most frequently spurred on the basis of ethnicity or religion, but they also occur due to economic development. Banishment or exile is a similar process, but is forcibly applied to individuals and groups. Population transfer differs more than simply technically from individually motivated migration, but at times of war, the act of fleeing from danger or famine often blurs the differences. If a state can preserve the fiction that migrations are the result of innumerable "personal" decisions, the state may be able to claim that it is not to blame for the displacement.

Forced displacement is an involuntary or coerced movement of a person or people away from their home or home region. The UNHCR defines 'forced displacement' as follows: displaced "as a result of persecution, conflict, generalized violence or human rights violations".