A concentration camp (or internment camp) is a place where a government forces people to live without trial. Usually, those people belong to groups the government does not like. The term means to confine (keep in a secure manner) "enemy citizens in wartime or terrorism suspects".
Some governments put people in concentration camps because they belong to a certain religion, race, or ethnic group.
Usually, people are sent to concentration camps without having had a trial or being found guilty of a crime.