The creditor is the owner of the bond. After $n$ years she/he will get $F$ Dollars from the debitor. This F Dollars are the **future value**. To get the present value $F$ Dollars have to be discounted $n$ years. $r$ is the interest rate for riskless investments. And $1+r$ is the discount factor. Therefore the **present (face) value** is
$$PV=\frac{F}{(1+r)^n}$$
If you have a positive interest rate a particular amount of money (F) in present has a higher value than this particular amount of money in the future. To get $F$ in two years you have to invest _only_ $\frac{F}{(1+r)^2}$. After two years you will have $\frac{F}{(1+r)^2}\cdot (1+r)^2=F$