A sustained increase in the general price level of goods and services is called inflation.
Inflation means that money’s purchasing power is declining: the same amount of currency buys fewer goods and services than before. Economists distinguish a broad rise in prices from a change in the price of one product. If only coffee becomes more expensive, that is a relative-price change; if prices across the economy rise persistently, it is inflation.
Inflation is measured with price indexes that track baskets of goods and services. Consumer price indexes focus on household purchases, while measures such as the GDP deflator cover prices for domestically produced output. Central banks often aim for low, stable inflation rather than zero inflation; the U.S. Federal Reserve has described a 2% long-run inflation rate, measured by the PCE price index, as consistent with its mandate.
Hyperinflation is an extreme, rapidly accelerating form of inflation, not the general term. Stagflation combines inflation with weak economic growth and high unemployment, while deflation means the general price level is falling.