Social Darwinism is an early and now largely discredited view of social evolution emphasizing the importance of "survival of the fittest" or the struggle between individuals, groups, or societies as the motor of development. Social Darwinism became widely popular in the latter half of the nineteenth century and was often used to justify existing inequalities.
Social Darwinism is the application to human societies of Darwin's evolutionary theories of natural selection, where only the fittest members of a species survive. In effect it was (and is) an attempt to justify the existing orders by arguing that the rich and successful have evidently been selected by nature to be rich and successful.