it was the psychological and regime war of tensions between soviet union (USSR) and the west, mainly the United States
it started after world war 2 after the west and russia beat Germany together to establish the USSR and USA as the two main global powers in the world
USSR was communist and USA was capitalist, both their ideologies were directly opposite since USSR believed in world communism but USA and the west felt threatened by this, so both sides toppled regimes and did everything that WASN'T war between USSR and USA to one up the other, mainly because everyone was scared of the vast amount of nuclear weapons each sides had
some important topics to look at is the cuban missile crisis, afghanistan invasion, olympics boycott in 1980s, truman's doctrine, destalinization by krushchev, berlin blockade, berlin wall and how the USSR, and also the race to space
of course the USSR won