The term "Iron Curtain" was used by Winston Churchill to describe a divide between Western and Soviet spheres of influence.
Iron Curtain refers to the political, ideological, and in some cases physical border between Western Europe (Capitalist Bloc) and Eastern Europe (Communist Bloc), after World War II.
The former British Prime Minister Winston Churchill used it to refer to the border, not only physical but also ideological, which divided Europe into two blocs after the Second World War.
The frontier of which Churchill spoke divided the socialist states, headed politically, economically and militarily by the Soviet Union, and the capitalist states, aligned with the United States.