A credit rating is a measure of the credit worthiness of a government, a public entity, or a private corporation. The credit rating is also used as an assessment of the quality of debt instruments issued by any of these organizations.
[Moody’s] Credit Rating by Country, as of February 2013
As explained in the article Credit Ratings by S&P, Moody’s and Fitch Ratings, a “credit rating” is a measure of the ability of an entity, whether a company or a sovereign state, to repay its debt. It shows the quality of loan instruments issued by the borrowing entity and whether these debt instruments can be repaid on time.