A recession is a period of slowing economic growth that is usually marked by declines in employment and income, reduced consumer spending, and a decrease in investment. A depression is a more severe economic downturn, characterized by a deep and long-lasting decrease in economic activity. 
 

Gross domestic product (GDP) measures the total value of all goods and services produced within a country's borders, regardless of ownership. Gross national product (GNP) measures the total value of all goods and services produced by a nation's citizens, regardless of where the production takes place.

A market economy is an economic system in which the production and distribution of goods and services are determined by the interaction of supply and demand in a free market. In a market economy, prices are determined by the forces of supply and demand, and firms and consumers are free to make their own economic decisions.