There are many ways to classify bonds, but the most common is by the type of issuer. That is there are Government bonds, Municipal bonds, and Corporate bonds. Within this classification there can be many types of bonds ranging from short term-to consols, from callables to puttables, from convertibles to plain vanilla. The most widely known type of government bond is the US Treasury Bond. These are issued by the US Treasury and are backed by the full power of the US government.
Most countries issue similar types of securities.
These government IOUs can be further broken down along maturities. Those that are issued with a maturity of less than 10 years are generally called Treasury Notes. Generally T-Bonds pay coupons twice a year. These coupon payments are taxed at the Federal level but are exempt from State and Local taxes. Overall they are quoted as a n percentage of par, but the percentage is not as easy as a typical percentage.