What is 'AAA'

AAA is the highest possible rating assigned to an issuer's bonds by credit rating agencies. An AAA-rated bond has an exceptional degree of creditworthiness, because the issue can easily meet its financial commitments. The ratings agencies Standard & Poor's (S&P) and Fitch Ratings use the AAA to identify bonds with the highest credit quality, while Moody's uses AAA is the top credit rating.

Source: Investopedia