The Union of Soviet Socialist Republics (USSR) was a federal socialist state in Northern Eurasia that existed from 1922 to 1991. It was a one-party state governed by the Communist Party with Moscow as its capital.
Communism: A political theory derived from Karl Marx, advocating class war and leading to a society in which all property is publicly owned and each person works and is paid according to their abilities and needs.
Cold War: A period of geopolitical tension between the Soviet Union with its satellite states (the Eastern Bloc), and the United States with its allies (the Western Bloc) after World War II.
Iron Curtain: A term popularized by Winston Churchill representing Europe's division into mostly democratic Western Europe and Communist Eastern Europe during the Cold War.