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.
Aggregate income
GDP stands for gross domestic product. GDP is a measure of the economic output of a country. It is usually defined as the total market value of goods and services produced within a given period after deducting the cost of goods and services used up in the process of production, but before allowances for depreciation. Most countries compile estimates of their GDP based on guidelines from the United Nations.