Income, money or other economic gain or return in a given period of time, usually measured annually. Income may be received by an individual or by an entity, such as a corporation or a government.

The various types of income are usually described within the private sector or the public sector of economic activity. In the private sector the four major types of income are wages, the return for labour; rent, the return for use of land; interest, the return for the use of capital; and profit, the return to the business owner. Income in the public sector, called national income, is the money measure of the annual flow of goods and services in an economy, and is taken as the sum of all lesser incomes.

Income is normally measured in money terms, although nonmoney definitions are sometimes used, especially in economic theory. Real income refers not to the actual money income but to the extent that the money income can be used to purchase goods and services as they are affected by price changes.