The answer would be "Ghettos." During World War II, the Germans concentrated urban and sometimes regional Jewish populations in ghettos. Living conditions were miserable. Ghettos were often enclosed districts that isolated Jews by separating Jewish communities from the non-Jewish population and from other Jewish communities. The Germans established at least 1,000 ghettos in German-occupied and annexed Poland and the Soviet Union alone. There were three types of ghettos: closed ghettos, open ghettos, and destruction ghettos.