An ordinary annuity is a series of equal payments made at the end of each period for a specific duration. For instance, consider a scenario where \$1,000 is deposited into an account at the close of each year for the next ten years. This consistent stream of payments, occurring at the end of each period, represents an ordinary annuity. This contrasts with an annuity due, where payments are made at the beginning of each period.
Understanding the concept is crucial in financial planning, retirement savings, and investment analysis. Its application allows individuals and institutions to accurately project the future value of a series of payments or to determine the present value needed to fund a future stream of income. Historically, these financial instruments have played a significant role in providing structured payouts for retirement and managing long-term financial obligations.