What was the main idea of social Darwinism, and how did it compare with the idea of individualism?

The term Social Darwinism is used to refer to various ways of thinking and theories that emerged in the second half of the 19th century and tried to apply the evolutionary concept of natural selection to human society. The term itself emerged in the 1880s, and it gained widespread currency when used after 1944 by opponents of these ways of thinking. The majority of those who have been categorised as social Darwinists did not identify themselves by such a label