Hopefully you already knew that you're entitled to one free credit report every year from each credit reporting company. However, you might think that you only get three reports out of the deal (one from Equifax, one from TransUnion, and one from Experian).
In fact, there are dozens of companies out there that collect and sell data that fall under the rules providing free credit reports. These organizations track plain-old financial information, similar to traditional credit bureaus, and they also keep data about your insurance and employment history -- among other things. You're allowed to see this information simply by asking for it, just like you're allowed to see your credit reports for free.
If you're confused, you're not alone. Some of these companies don't even know that they're supposed to provide free reports for consumers (or they prefer not to follow the rule). As a result, the Consumer Financial Protection Bureau (CFPB) sent a warning to these companies urging them to follow the rules. The CFPB also provides a list of some of these consumer reporting agencies, so you can get in touch with them if you want to.