An annuity is a contract between you and an insurance company. You pay either a single lump sum or a series of contributions, and in return the provider pays you a stream of guaranteed income — either right away or starting on a date you choose.
The appeal is predictability. Unlike investments tied to the daily market, the right annuity can deliver income you can count on month after month, including income that lasts as long as you live.
Different products balance growth, protection, and access in different ways, so the best fit depends on when you need income, how much risk you're comfortable with, and what other retirement savings you already have in place.