the loss of value of money caused by disproportionate and sudden rising prices;
occurs when the quantity of money in circulation exceeds the value of the goods and services offered, or when
the public loses confidence in the national currency, precipitating a widespread and sudden rush to convert money into real goods.
In mundane terms, inflation happens when a given product or service suddenly costs much more money to buy than before.
Inflation can be measured in two different ways:
From the consumption standpoint, inflation is usually measured by a Consumer price index that tracks price changes of a selected "basket" of goods over a given period of time.
However, from the whole economy standpoint (consumption, investment, imports, exports, various economic sectors, etc.) inflation is measured by the GDP deflator, calculated as the ratio of the current and constant prices at which the volume of goods and services that build the GDP (Gross Domestic Product) may be evaluated.