Answer:
You would expect a bond of the U.S. government and a bond of an Eastern European government to pay different interest rates because of differences in the bonds Credit Risk.
The United States has the safest securities in the World and so pay different rates from other countries to reflect this especially with an Eastern European Government that is not as trusted.
You would expect a bond that pays the principal in year 2040 and a bond that pays the principal in year 2020 to pay higher interest rates because of differences in the bonds.
Bond with longer maturity terms are riskier as they will be exposed to more inflation and interest rate risk.
You would expect a bond from a software company you run in your garage and a bond from Coca-Cola to pay different interest rates because of differences in the bonds Credit Risk.
Coca-Cola is a big company with many assets that back up any leverage it has and so they will have a lower risk than a person with a small business in a garage that might be unable to keep up with payments and default.
You would expect a bond issued by New York State to pay higher interest rate as compared to a bond issued by the federal government.
The Federal Government will be less riskier than New York when it comes to repaying debt because if push comes to shove they can simply print more dollars. They also have higher revenue streams than New York State which means that New York is riskier and will therefore pay a higher interest rate to compensate.