GDP is the total market value of all final goods and services produced in an economy in a year. GDP is composed of consumption, investment, government expenditures, and net exports. GDP can increase due to higher prices, more output being produced, or a combination of both. Inflation is measured by percentage changes in price indexes like the GDP deflator or CPI and is used to calculate real GDP, real wages, and real interest rates by adjusting for price changes over time. Unemployment is linked to economic output through Okun's Law, which states that a 1% increase in unemployment results in a 2% decrease in potential GDP.