Bonds
A bond is simply an IOU. It is an agreement under which a sum is repaid to an investor after an agreed period of time.
A bond can be issued by anyone but is, generally, a certificate issued by a government (see gilts ) or a public company to repay money borrowed.
These loans normally repay a fixed rate of interest over a specified time and then also repay the original sum at par in full after an agreed period - when the bond matures.