Investment income refers to the earnings generated from investing money in various assets such as stocks, bonds, mutual funds or real estate. This type of income is typically earned through interest payments on loans made to others (such as bondholders), dividends paid by corporations, and capital gains realized upon selling an asset for a profit. Investment income can be received regularly, such as in the form of monthly or quarterly dividend payments, or it may come only when the investment is sold or matures. It's important to note that investment income does not include wages or salary earned from employment.