Nazi racial policy classified people as racially ‘superior’ or ‘inferior’. According to these principles, the German people (Volk) belonged to the superior ‘Aryan race’ which had to be kept ‘pure’. The pseudo-scientific concept of ‘racial hygiene’ was applied for this purpose. Although the National Socialists had not devised the concept, they implemented it with methods that resulted in murder. In the National Socialist world view, Jews and people with disabilities were the chief source of ‘contamination’ and a threat to the ‘Aryan race’ and were ultimately to be eradicated.

For more information (in German) see: LeMO NS-Regime – Innenpolitik – Rassenpolitik (dhm.de)