The S&P, or Standard & Poor's, is a financial services company known for its stock market indices, particularly the S&P 500. This index tracks the performance of 500 of the largest publicly traded companies in the United States, providing a snapshot of the overall market health. Investors and analysts often use the S&P 500 as a benchmark to compare the performance of individual stocks or investment portfolios. In addition to the S&P 500, the company offers various other indices and ratings that help assess the creditworthiness of corporations and governments. These ratings influence investment decisions and can impact borrowing costs for entities seeking loans or issuing bonds.