What is the difference between an attestation standards vs auditing standards?

Michael, the difference is in the applicability to the financial statements. An attestation standard applies to agreed-upon procedures, SSAE 16, and other types of assurance reports which are not necessarily material or relevant to the overall quality and accuracy of financial statement design, preparation, and presentation. You (the CPA firm) are reporting on management's assertions and your process for testing these assertions - as well as, obviously, the results of these tests. I hope this is helpful.