Traditionally, idealism places ideas before material reality, while materialism places material reality before ideas. Idealism isn’t usually a deliberate choice.

An example of idealism in practice would be “Great Man Theory,” the idea that history is driven by great men and their great ideas. Materialism asserts the opposite, that production and material forces are the driving force of history, and that historical leaders aren’t special people. Don’t confuse this as the idea that leaders have no power, more that, say, figures like Lenin are remembered because of their achievements, Lenin wasn’t destined from birth as a special being.