This document provides definitions and explanations of key concepts in macroeconomics including:
1) It defines macroeconomics as the study of aggregate economic variables of an economy.
2) It explains the circular flow of income and how it refers to the cycle of generation, distribution, and circulation of income between households and production units.
3) It discusses different methods of calculating national income including the value added method, expenditure method, and income method.
4) It provides definitions of related concepts like GDP, GNP, NNP, consumption and capital goods, stock and flow, and instruments of monetary policy.