The Holocaust genocide of the European Jews during World War II.
Kristallnacht was a pogrom against Jews carried out by SA paramilitary forces and civilians throughout Nazi Germany on 9–10 November 1938.
Genocide is a mass extermination of a whole group of people, an attempt to wipe them out of existence.
Ghetto could be a part of a city especially a slum area, occupied by a minority group or groups.
a place where large numbers of people are detained or confined under armed guard