The Cold War was a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc, that started in 1947, two years after the end of World War II, and lasted until the fall of the Soviet Union in 1991.
The term cold war is used because there was no large-scale fighting directly between the two superpowers, but they each supported opposing sides in major regional conflicts, known as proxy wars.
The Cold War was based on an ideological and geopolitical struggle for global influence by these two superpowers, following their roles as the Allies of World War II that led to victory against Nazi Germany and Imperial Japan in 1945.