A country's Gross Domestic Product is the total value of the goods and services it produces in one year. GDP is used as a measurement of the size of a country's economy, and GDP growth is used as a measurement of economic growth - for example, in the US, two consecutive quarters of negative GDP growth is the official definition of a recession.
GDP = C + I + G + NX,
Components of GDP:-
Gross Imports - Imports are subtracted since imported goods will be included in the terms G, I, or C, and must be deducted to avoid counting foreign supply as domestic.