Annuity is a series of acceptance or a fixed payment made periodically at a certain time period. An example is the interest received from bonds or a cash dividend of preferred stock.
There are two types of annuities:
1. Ordinary annuity (ordinary) is the annuity payment or acceptance that occurs at the end of the period, and
2. Annuity due (due) is the annuity the payment or receipt made in the beginning of the period.