Gross domestic product
Gross domestic product (GDP) is a monetary measure of the market value of all the final goods and services produced in a period of time, often annually 
GDP (nominal) per capita does not, however, reflect differences in the cost of living and the inflation rates of the countries; therefore using a basis of GDP per capita at purchasing power parity (PPP) is arguably more useful when comparing differences in living standards between nations.
National Income and Product Accounts
The sum of the four production categories is gross domestic product, the value of all domestic expenditures on goods and services. GDP (income) must equal GDP (production) except for any rounding error that accumulates when the data used to prepare a table includes rounding at prior stages of analysis, as appears to have happened in this case.