A government bond or sovereign bond is a form of bond issued by a government to support public spending. It generally includes a commitment to pay periodic interest, called coupon payments, and to repay the face value on the maturity date.
For example, a bondholder invests $20,000, called face value or principal, into a 10-year government bond with a 10% annual coupon; the government would pay the bondholder 10% interest ($2000 in this case) each year and repay the $20,000 original face value at the date of maturity (i.e. after 10 years).
Government bonds can be denominated in a foreign currency or the government's domestic currency. Countries with less stable economies tend to denominate their bonds in the currency of a country with a more stable economy (i.e. a hard currency). When governments with less stable economies issue bonds, there is a possibility they will be unable to repay bondholders, resulting in a default. All bonds carry a default risk. International credit rating agencies provide ratings for each country's bonds. Bondholders generally demand higher yields from riskier bonds. For instance, on May 24, 2016, 10-year government bonds issued by the Canadian government offered a yield of 1.34%, while 10-year government bonds issued by the Brazilian government offered a yield of 12.84%.
Governments close to a default are sometimes referred to as being in a sovereign debt crisis.