Other forms: concentration camps
A concentration camp is a large facility where people are imprisoned for political reasons, not because they've done anything wrong. During World War II, Nazi Germany held more than a million people in concentration camps.
People in concentration camps are treated cruelly, forced to do physically difficult work, and are frequently sick and malnourished. The Nazi party established more than 1,000 camps during World War II, imprisoning Jews and other groups of people. Millions of them died — some were deliberately killed, and others perished from the harsh conditions. Concentration camp comes from the idea of assembling or "concentrating" a targeted group in one place, where the government can more easily control them.