Fixed-income or bonds refer to the debt issue by a company. When a company wants to borrow money from the public, it will issue bonds. Lenders or investors buy these bonds. These bonds will pay a regular fixed interest through the tenure of the bond. When the bond matures, the company returns the "par" or face value of the bond.

 

The risks of fixed-income are 

a) default risk (i.e. the company simply has no money to repay its obligations), 

b) interest rate risk, when interest rate rises, the bond value decreases in value

c) maturity period risk (i.e. the longer the maturity period the greater the sensitivity to interest rate risk)

d) Credit risk (i.e. if the company is viewed as less credit worthily, the bond value decreases)

e) Foreign currency risk if the bond is denominated in foreign currency

f) Liquidity risk (i.e. there may not be sufficient buyer/seller in the market place)

g) Non-systematic risk (i.e. company's insider trading, fraud, mismanagement, etc)

Fixed-income portfolio means that the investor invests in many bonds usually through a fund. By investing a large basket of fixed-income, non-systematic risk can be eliminated by the remaining risk remains.