Consumer Price Index (CPI) is a measure of the average change over time in the prices paid by urban consumers for a market basket of consumer goods and services.
Deflation is a general downward movement of prices for goods and services in an economy.
Depression is a very severe recession; a period of severely declining economic activity spread across the economy (not limited to particular sectors or regions) normally visible in a decline in real GDP, real income, employment, industrial production, wholesale-retail credit and the loss of the overall confidence in the economy.
Inflation is a general upward movement of prices for goods and services in an economy.
Nominal Gross Domestic Product (GDP) is the market value of all final goods and services produced within a country in a year.
Real Gross Domestic Product (GDP) is the production of all final goods and services within a country valued at constant prices (i.e., adjusted for inflation or deflation).
Unemployment rate is the percentage of the labor force who are unemployed.