1) Published tests (also known as commercial tests) are copyrighted tests that must be purchased directly from the publisher, and they typically require users to qualify as test administrators before purchases are approved. Published tests can be quite expensive and are generally not sold to libraries.
2) Unpublished tests are not sold commercially. These can be found in a variety of places, including journal articles, dissertations and books. Copyright restrictions vary among unpublished tests, so contacting the author for permission is always recommended.