Explain the significance of: populism, greenbacks, inflation, deflation

Populism is the belief that the power belongs to the people. However, in modern times it has become synonymous with only saying what the masses want to hear. Greenbacks was the currency of the civil war US. Their worth wasn't based on silver or gold but rather on the credibility of the country and its government. Inflation and deflation are economic concepts regarding determining the value of money. Inflation reduces it's value while deflation increases it.