There are different kinds of audits. When our student audited he was able to fully participate, completing all assignments and taking all tests and receiving back grades and feedback. The only difference between was that he did not earn credit or a grade reported on a transcript. Especially for younger students or homeschooled students who want to start college work, this is a great place to start. It is low risk, but the student still gets good experiences. Not every instructor or every school will allow it but it never hurts to ask.