Nominal GDP:  value of output produced in current prices. Price (x) quantity.

Real GDP: the value of output produced in constant or base year prices.  Price X quantity.

Price index: measures insulation by tracking changes in the price of a market basket of goods compared with the base year. ( add up all the nominal GDP)

GDP deflator: is a price index used to adjust from nominal to real GDP.
       - in the base year GDP will equal 100.
       - years after the GDP deflator is more than 100.
       - years before base year GDP deflator is less than 100.
       - equation: (nominal GDP divided by real GDP) X 100.

How to calculate inflation:
    - formula: ( new GDP deflator - old GDP deflator divided by old deflator) X 100.