Inflation refers to a sustained increase in the general price level of goods and services in an economy. It results from an imbalance between the supply and demand for money. When there is too much money supply, prices rise as each currency unit buys fewer goods. This leads to a reduction in purchasing power. Deflation is the opposite of inflation, where the general price level declines. Hyperinflation refers to an extreme case where prices increase rapidly in a short period of time, potentially causing an economic breakdown. Stagflation is when high unemployment and economic stagnation occur alongside inflation.