The terms First World, Second World, and Third World were originally used to divide the world's nations into three categories. The model did not emerge to its end state all at once. The complete overthrow of the pre–World War II status quo, known as the Cold War, left two superpowers (the United States and the Soviet Union) vying for ultimate global supremacy. They created two camps, known as blocs. These blocs formed the basis of the concepts of the First and Second Worlds.