A bond is a fixed income instrument that represents a loan from an investor to a corporation or government. A bond is considered a fixed income security that is throughout of as an IOU between the individual lender and borrower with terms that outline the details of the loan and its regular payments. A bond is equipped with an end date when the principal of the loan is due back to the borrower in addition to the specific coupon amount that is due to the lender on a payment schedule, based on the variable or fixed interest rate assigned to the loan.