National Income Accounting is a system used by governments to measure a country's economic performance. It tracks the total income earned by individuals and businesses, as well as the total expenditure on goods and services within a specific period. This information helps policymakers understand the economy's health and make informed decisions. The main components of National Income Accounting include Gross Domestic Product (GDP), Gross National Product (GNP), and Net National Product (NNP). These metrics provide insights into economic growth, productivity, and overall living standards, allowing for comparisons over time and between different countries.