GDP, or Gross Domestic Product, is a monetary measure that represents the market value of all final goods and services produced in a country during a specific period, typically annually or quarterly. It is used as an indicator of a country's economic health, reflecting the size and performance of its economy. Higher GDP often suggests a more prosperous and productive economy, while lower GDP points to economic challenges. Economists assess GDP to understand trends, make comparisons between nations, and formulate economic policy. It can be calculated using three approaches: production, income, and expenditure.