Annuities provide guaranteed income, death benefits, and tax-deferred growth for retirement. Immediate annuities start payments within 12 months, ideal for those near or in retirement, while deferred annuities delay payments, allowing tax-deferred growth, suited for those years away from retirement. Types include fixed, variable, and indexed annuities. Risks include inflation, market fluctuations, and limited liquidity. Annuities complement other retirement income sources but require careful consideration.