Bond pricing

FI (fixed income) securities are traded in market like stocks, so they too have price.
The price of the bond is determined by the :

1. The current rates prevalent in the market
2. Future interest rate expectations
3. Credit quality of the issuer

Like any other asset, the price of the FI security is a present value of the future cash flows.
Bonds and interest rates inverse relation
Bonds price in secondary markets 
Calculating bond price