A bond is basically an I.O.U. or promissory note of a corporation or municipality, usually issued in multiples of $1,000 or $5,000.
A bond is evidence of a debt on which the issuing company usually promises to pay the bondholder a specified amount of interest for a specified length of time, and to repay the loan on the expiration date.
A bondholder is a creditor of the corporation. Unlike a shareholder, a bondholder is not a partial owner of the company.