Cultural hegemony is the philosophic and sociological concept, originated by the Marxist philosopher Antonio Gramsci, that a culturally-diverse society can be ruled or dominated by one of its social classes. It is the dominance of one social group over another, e.g. the ruling class over all other classes. The theory claims that the ideas of the ruling class come to be seen as the norm; they are seen as universal ideologies, perceived to benefit everyone whilst only really benefiting the ruling class.
Reference: Wikipedia – Cultural hegemony