Definition of [real] gdp (significance of final goods and services" and concept of value added"; produced within a country; for a time period; evaluated at market [base year] prices. Distinction of nominal gdp and real gdp. Why expenditure equals income (the expenditure and income approach to calculating real gdp. Definition of business cycle (peak, trough, expansion and recession phases) Limitations of real gdp (household production; underground economic activity; environmental quality) Gdp or gross domestic product is the market value of all final goods and services produced in a country in a given time period. This definition has four parts: market value , final goods and services , produced within a country , in a given time period. Gdp is a market value goods and services are valued at their market prices. To add apples and oranges, computers and popcorn, we add the market values so we have a total value of output in dollars.