An annuity is basically the exact opposite of life insurance. While proceeds of life insurance are paid at the time of death of the insured, the proceeds of an annuity are paid while the annuitant is alive. Generally, the annuitant can never outlive the income from the annuity. However, you can also purchase an annuity which will provide income only for a specified period of time.
Annuities are primarily intended to provide a source of retirement income. Payments can be made to the annuitant monthly, quarterly, semi-annually or annually. While there are many types of annuity products available, they can be classified into three general categories: single premium immediate payment annuities, deferred annuities and variable annuities. Both the deferred and variable types are available on a single premium or flexible premium basis.