Nazi Germany used six extermination camps, also called death camps, or killing centers, in Central Europe during World War II to systematically murder over 2.7 million people – mostly Jews – in the Holocaust. The victims of death camps were primarily murdered by gassing, either in permanent installations constructed for this specific purpose, or by means of gas vans. The six extermination camps were Chełmno, Belzec, Sobibor, Treblinka, Majdanek and Auschwitz-Birkenau. Extermination through labour was also used at the Auschwitz and Majdanek death camps. Millions were also murdered in concentration camps, in the Aktion T4, or directly on site.

Holocaust victims were people targeted by the government of Nazi Germany based on their ethnicity, religion, political beliefs, disability or sexual orientation. The institutionalized practice by the Nazis of singling out and persecuting people resulted in the Holocaust, which began with legalized social discrimination against specific groups, involuntary hospitalization, euthanasia, and forced sterilization of persons considered physically or mentally unfit for society. The vast majority of the Nazi regime's victims were Jews, Sinti-Roma peoples, and Slavs but victims also encompassed people identified as social outsiders in the Nazi worldview, such as homosexuals, and political enemies. Nazi persecution escalated during World War II and included: non-judicial incarceration, confiscation of property, forced labor, sexual slavery, death through overwork, human experimentation, undernourishment, and execution through a variety of methods. For specified groups like the Jews, genocide was the Nazis' primary goal.