What did Churchill mean by the 'Iron Curtain'?

Answer 1

The term iron curtain referred to the divide of Europe into two sides. (The separation of the Communist countries in Eastern Europe from the democratic nations in the West.) This 'iron curtain' lasted from 1945 until 1991.

Answer 2

On 5th March, 1946 Winston Churchill gave a speech at Westminster College, Fulton Missouri, on the ocassion of being given an honorary degree. Following the end of World War 2, Europe had become divided between East and West, the East being under control of Soviet Russia. The expression "Iron Curtain" refers to the tanks, guns and other armaments and physical barriers with which the Soviets enforced their control. Here is the part of his speech containing the reference: "A shadow has fallen upon the scenes so lately lighted by the Allied victory. Nobody knows what Soviet Russia and its Communist international organization intends to do in the immediate future, or what are the limits, if any, to their expansive and proselytizing tendencies. I have a strong admiration and regard for the valiant Russian people and for my wartime comrade, Marshal Stalin. There is deep sympathy and goodwill in Britain - and I doubt not here also - towards the peoples of all the Russias and a resolve to persevere through many differences and rebuffs in establishing lasting friendships. We understand the Russian need to be secure on her western frontiers by the removal of all possibility of German aggression. We welcome Russia to her rightful place among the leading nations of the world. We welcome her flag upon the seas. Above all, we welcome constant, frequent and growing contacts between the Russian people and our own people on both sides of the Atlantic. It is my duty however, for I am sure you would wish me to state the facts as I see them to you, to place before you certain facts about the present position in Europe. From Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the Continent. Behind that line lie all the capitals of the ancient states of Central and Eastern Europe. Warsaw, Berlin, Prague, Vienna, Budapest, Belgrade, Bucharest and Sofia, all these famous cities and the populations around them lie in what I must call the Soviet sphere, and all are subject in one form or another, not only to Soviet influence but to a very high and, in many cases, increasing measure of control from Moscow"
Winston Churchill meant that Russia had build a wall separating eastern europe from Western Europe.