Interest is the remuneration paid or received as consideration for the assignment of a given amount of money.
Interest is the extraordinary amount to be paid by the person requesting a loan and the amount charged by the lender as remuneration for the temporary assignment of capital. It is the cost of the debt to the debtor.
The interest serves to compensate the party that is going to lose the availability of its capital, creditor, for putting it at the service of the debtor.
If we talk about an investment or a deposit, the interest is the amount of money that produces a capital that is invested.
It is a concept closely related to the interest rate, since it is the result of applying the latter to an amount. In other words, the amount resulting from applying the interest rate is the interest.