Auschwitz-Birkenau was the largest Nazi concentration and extermination camp established during World War II, located in German-occupied Poland. It served as a central site for the systematic genocide of Jews and other targeted groups, playing a crucial role in the Holocaust. The camp complex included Auschwitz I, the administrative center; Auschwitz II (Birkenau), which was primarily an extermination facility; and Auschwitz III, dedicated to forced labor.