There is no difference between par value and face value when it comes to the value of financial instruments. Both words relate to the financial instrument’s declared value at the moment it is issued.
When it comes to bonds, par value is more often used than when it comes to stocks. The par value of a bond is the amount of money that the bond issuers promise to refund to the buyer when the bond matures. A bond is essentially a written guarantee that the issuer will be paid back the amount borrowed.