Hitler and the Nazis had firm views on race.
They believed that the Germans were Aryans and therefore the "Master Race".
Most other races were categorised as slave races, but some groups were labelled ‘untermensch’ or sub-human. The Slavs of Eastern Europe, “gypsies” (such as Sinti or Roma) and Jews were regarded as such.
The Nazis believed that all other groups were inferior to the Aryans and they were a threat to the purity of the superior “Master Race”, particularly the “subhumans”.
Many Nazi scientists believed in eugenics and selective breeding.
They believed that people with disabilities or social problems were degenerates whose genes needed to be eliminated from the human bloodline.