Was it a real war and what were some of the causes?
The us provided aid to countries about to fall to communism.
The soviets and United states were on completely different ends of the political spectrum. The Soviets were a communistic nation with a totalitarian leader while the US was a capitalistic democracy. This caused a lot of tension and conflict between the two.
The marshall plan also created tension between the two nations. The plan was basically the US's way to hinder the spread of communism in Europe. While the soviets had converted some eastern European countries to communists, the US worked hard to ensure it wouldn't take over. The divide between the communist, easter European countries and the other european countries was called the iron curtain.
Fun Fact: Despite it's name, the cold war wasn't a "real", physical war!
The truman doctrine was the US providing aid to countries that were close to falling into communism. The soviets responded to this with their own version of the marshall plan called Comecon.
When the US joined NATO, tensions grew even more. In responce to this the Soviet Union gathered it's eastern allies to develop their version of NATO called the warsaw pact.
The arms race intensified once again when the Soviets detonated the first successful atom bomb in 1949. Also, the US began to worry more about the spread of communism when the Soviet Union made an alliance with china.