In August 1945, a nuclear bomb was released on Japan which helped contribute to the end of the second world war but the start of the Cold War.
It also helped start the following wars like the Korean and Vietnam Wars which had both things in common and differences.
One major difference between the two wars was the type of fighting. For example, in the Korean War they fought in short bursts; however, in the Vietnam War the fighting was long and drawn out.
One way they were similar was the fact that they were both proxy wars, which means they used other countries as substitutes for fighting each other directly. They also both had roots in the Truman Doctrine and were split into two parts in the war.