An annuity is an insurance product that pays out income, and can be used as part of a retirement strategy. Annuities are a popular choice for investors who want to receive a steady income stream in retirement.Here’s how an annuity works: you make an investment in the annuity, and it then makes payments to you on a future date or series of dates. The income you receive from an annuity can be doled out monthly, quarterly, annually or even in a lump sum payment.The size of your payments are determined by a variety of factors, including the length of your payment period.You can opt to receive payments for the rest of your life, or for a set number of years. How much you receive depends on whether you opt for a guaranteed payout (fixed annuity) or a payout stream determined by the performance of your annuity’s underlying investments (variable annuity).While annuities can be useful retirement planning tools, they can also be a lousy investment choice for certain people because of their notoriously high expenses. Financial planners and insurance salesmen will frequently try to steer seniors or other people in various stages toward retirement into annuities. Anyone who considers an annuity should research it thoroughly first, before deciding whether it’s an appropriate investment for someone in their situation.