A cold war is a state of conflict between nations that does not involve direct military action but is pursued primarily through economic and political actions, acts of espionage or conflict through surrogates. The surrogates are typically states that are "satellites" of the conflicting nations, i.e., nations allied to them or under their political influence.
The most famous cold war, c. 1945-1990, was the conflict between the United States and its NATO allies — loosely described as the West — and the former Soviet Union and its Warsaw Pact allies — loosely described as the Eastern bloc. For an in-depth article about this confict, see Cold War.
United States vs. Soviet Union
Other cold wars