The difference between test reports are:
First of all, there is no such thing as certification by the FDA itself, and it is called accreditation only because it is convenient for us to say so. Since there is no accreditation, there is no certificate, so the so-called certificates that many service organizations have come up with are actually of no real use.
The FDA can be referred to as a registry, and the registry is based on specific products to determine the process and the documents that need to be submitted. For example, some medical devices, you need to apply for the 510K code, and to apply for this code you need to provide the relevant documents to prove that a product to achieve the safety characteristics of products already on the market, how to prove that involves the relevant standards and standards for testing, here is what you call the FDA testing.
There is no requirement for this testing to be done by any organization, it is a form of self-assurance. But the testing of medical devices is really only done by those organizations.
There are also FDA tests for other types of products, such as food contact materials, cosmetics, and whatnot, which are based on regulations set by the FDA.