Why is Winston Churchill’s speech known as the ‘Iron Curtain speech’?

In the "Iron Curtain speech" Winston Churchill drew attention to the fundamental split in Europe between the Eastern Bloc and the West, though at that stage (March 1946) there were no formal alliances. He had a fear of another world war that involves fighting against the communist regime and that the so called iron curtain is blocking some of the countries connection to the western countries because of the communist terror.

Iron Curtain speech, Winston Churchill, Europe, Eastern Bloc, West, Alliances, Communist regime, Iron curtain, Western countries, Communist terror