This document summarizes the key facts and arguments about the Holocaust and mass killings in Europe during the 1930s and 1940s. It argues that the Holocaust was centered in Poland and the Soviet Union, where the majority of Jewish victims lived, rather than Auschwitz. It also notes that Nazi Germany carried out mass killings of non-Jewish Slavic populations and that Stalin's Soviet Union deliberately starved and executed millions of civilians, with Belarus, Ukraine, Poland and the Baltic states experiencing the highest death tolls from both regimes' policies of mass killing.