Credit ratings are assessments of the creditworthiness of individuals, companies, or governments. They are typically provided by agencies like Moody's, Standard & Poor's, and Fitch. These ratings help lenders determine the risk of lending money and influence the interest rates borrowers will pay. A credit rating is expressed as a letter grade, such as AAA for the highest quality and D for default. Higher ratings indicate lower risk, while lower ratings suggest higher risk. These ratings play a crucial role in financial markets, affecting everything from loan approvals to investment decisions.