The scope of macroeconomics can be described as below:
(i) Theory of Income and Employment: Macroeconomics studies national income, its different assumptions, methods of measurements, social accounting, etc. It also includes study related to determination of equilibrium level of income and employment. National income and the level of employment depend upon effective demand. For the analysis of effective demand, total demand, total supply, total consumption, total investment, total saving, multiplier etc. are studied.
(ii) Theory of Money: In macroeconomics, the principles of capital are studied. Macroeconomics also studies the functions of money, changes in demand for and supply of money, and theories relating to money, banks and financial institutions.
(iii) Theory of Trade Cycles: Macroeconomics studies the fluctuations in the country's economic activities such as aggregate production, employment, interest rates, trade, general price level, etc.
(iv) Macro Theory of Distribution: It deals with the study of relative shares of labourers and capitalists, in the form of wages and profits respectively, in the total national income.
(v) Theory of Growth: Macroeconomics studies the rate and level of economic development. Economic growth includes growth or changes due to increase in per capita real income. Public finance and financial policies of the government can also be studied by using macroeconomics.

Following points explain the difference between microeconomics and macroeconomics:

Microeconomics and macroeconomics are interdependent as:
(i) Investment in one industry depends upon the level of investment in the economy as a whole.
(ii) Aggregate Demand in macroeconomics is the sum total of demand at the micro level.

Macroeconomic paradox is a term that captures the point that what may be true for an individual might not essentially be true for the economy as a whole.

Following are the five variables of macroeconomics:
(i) Theory of Income and Employment
(ii) Theory of Money
(iii) Trade Cycle
(iv) Macro Theory of Distribution
(v) Growth Economics

Following are the four major sectors in an economy:
(i) Household Sector: By household, we mean a group of individuals who purchase goods and services for consumption.
(ii) Firm/Production Sector: The production units are called firms. The firm sector includes all the units that buy factors of production from households.
(iii) Government Sector: The role of the government sector includes framing laws, enforcing them and delivering justice. The government, in many instances, undertakes production apart from imposing taxes and spending money on building public infrastructure, running schools, colleges, providing health services, etc.
(iv) External Sector: The external sector includes exports and imports of goods and services. Capital from foreign countries may also flow into the domestic country, or the domestic country may be exporting capital to foreign countries.

Following are the important features of a capitalist economy:
(i) There is private ownership of means of production.
(ii) Production takes place for selling the output in the market with profit as the primary motive.
(iii) Prices of goods and services are determined by market forces of demand and supply with minimum intervention by the government.
(iv) Consumers are free to choose whatever they can afford.