TransUnion, Equifax and Experian are the big three credit rating agencies in the United States.
Each have their own credit report, their own credit scores and their own records.
They all collect the information on you and your history.
Their profits come from sharing that information with banks, mortgage lenders, potential landlords and even sometimes employers and insurance companies.
You can get a free credit report one time each year from each company and it is a good idea to make sure that you get all three. Check out annualcreditreport.com for more info.