Fair Isaac is not a credit bureau. Fair Isaac Corporation is the company that was the leader in developing credit scores. They develop a credit score known as the FICO score which is not the most popular credit scores used by consumers and lenders alike. You can access your FICO credit score by buying it directly from myFICO.com. It is also possible to buy your credit report from two of the three national credit years from myFICO.com.
The 3 major national credit bureaus are Equifax, Experian and TransUnion. They are the ones that most of the creditors report to with the transaction data of their consumers and subsequently use the credit reports and scores available to with them for the purpose of approving new credit applications.