The Holocaust was the systematic, state-sponsored persecution and murder of six million European Jews by the Nazi German regime and its allies and collaborators between 1933 and 1945 across Europe and North Africa. The term Holocaust, derived from a Greek word meaning "burnt offering," has become the most common word used to describe the Nazi extermination of Jews in English and many other languages. The murders were carried out primarily through mass shootings and poison gas in extermination camps, chiefly Auschwitz-Birkenau, Treblinka, Belzec, Sobibor, and Chełmno in occupied Poland. The Holocaust also targeted other groups, including the Roma and Sinti, Soviet prisoners of war, and Polish and Soviet civilians, for different reasons. The Holocaust was a foundational part of Western culture and is a fundamental part of the history of the Second World War. The Holocaust has been commemorated in memorials, museums, and speeches, as well as works of culture such as novels, poems, films, and plays. Holocaust denial is a criminal offense in some countries.