Nominal Vs. Real GDP
Nominal GDP (NGOP): Measures GDP in current dollars no matter what the output is (PxQ)
Real GDP (RGDP): Measures GDP in constant dollars and adjusted inflation (New Q x Base Year P)


GDP Deflator
Measure of level of prices of all new domestically produced final goods/services in an economy 
(Nominal GDP/Real GDP) x 100   

Inflation Rate
Rise in general level of prices
(((price index in yr 2)-(price index in year 1))/(price index in year 1)) X 100

CPI
Consumer Price Index
Most widely used measure of the overall price level in the US
((Price of the market basket in the particular year)/(Price of the same market basket in year ____)) X100