Net national income is defined as the total amount of income earned by a country's residents or citizens minus the amount paid to foreigners for the goods and services produced within the country. It is an important economic indicator used to measure a country's economic performance and its citizens' standard of living. Some of the synonyms for net national income include national income, gross national income, per capita income, disposable income, and personal income. These different terms are used interchangeably depending on the particular context. For instance, gross national income is a measure of a country's total economic output while per capita income is a measure of average income per person.