Inflation is the rate at which the general level of prices for goods and services is rising and, consequently, the purchasing power of currency is falling.
Deflation or price deflation, is a general decrease in the price level. This may seem like a great thing for shoppers, except that the cause of widespread deflation is a long-term drop in demand. It means that a recession is probably underway.
Source: https://www.investopedia.com/terms