Highest rating of creditworthiness and, therefore, the expected financial solvency of a company or country. It is spelled "Triple A".
Rating agencies assess the creditworthiness of borrowers and thus the likelihood that borrowers will meet their payment obligations as agreed. These agencies create their ratings on a systematic approach, assigning scores from AAA (spelled "Triple A") for the best to D for "almost hopeless" that debtors will be able to meet their payment obligations in the long run. The better the rating, the better the conditions a company or a country can raise capital through the capital markets. This rating helps investors making their investment decisions.
In addition to ratings for bonds issued by governments, banks or industrial enterprises, the agencies assign ratings for money market instruments and, in recent years, for investment funds.
Standard & Poor's, Fitch and Moody's are well-known rating agencies.
You will find an overview of the rating grades and their meanings of several rating agencies on boerse-frankfurt.de/rating.