While the term Holocaust generally refers to the systematic mass murder of the Jewish people in German-occupied Europe, the Nazis also murdered a large number of non-Jewish people who were also considered subhuman (Untermenschen) or undesirable. Some victims belonged to several categories targeted for extermination, e.g. an assimilated Jew who was a member of a communist party or someone of Jewish ancestry who identified as one of Jehovah's Witnesses.