Explain in detail who could be considered "civilized" and "uncivilized" according the theory of Social Darwinism.?

The theory of Social Darwinism advocates that the most suited race will win and natural selection will play out. It was used to promote the white european race and to justify the holocaust and other horrors of the past. Since there were facists governments on the rise at that time, they classified the white european race as "civilized" and the other races as "uncivilized" and inferior to them.