Annuities are contracts, or a form of investment, between two parties.  The investor makes an investment and the financial institution (usually an insurance company) agrees to repay the investor, with interest, over different time intervals. Typically, you would make either one lump-sum payment or a series of payments to your insurance company, and in return the insurance company would pay back your investment at agreed points in time and an agreed interest rate. There are three types of annuities: fixed, variable and equity-indexed annuities.