This document discusses key concepts related to measuring a nation's economy, including: 1) Gross Domestic Product (GDP) measures the total market value of goods and services produced in a country in a year. It can be calculated using expenditure, income, or production approaches. 2) GDP only includes final goods and services sold to end users and excludes intermediate goods to avoid double counting. 3) National income accounts track GDP and the circular flow of spending and income between households, firms, and the government. 4) While GDP provides a useful measure, it has limitations such as excluding non-market activities and failing to account for environmental and social costs. Price indexes are used to adjust GDP for