Hyperinflation is a condition in which the rate of inflation is in an uncontrollable advancing state. When inflation exceeds several hundred or several thousand percentage points, hyperinflation is in effect, and a country's money becomes greatly devalued. In this state, the price of goods also rise sky high, causing a currency's purchasing power to plummet.
The U.S. dollar has yet to fall victim to hyperinflation.
When a country is hit with hyperinflation, the barter system is likely to become more beneficial than the standard medium of exchange.