Most publishers use one of two mechanisms for transferring copyright or licensing a work for publication. Additionally, most publishers distinguish between different versions of an author's work for purposes of self-archiving and distribution. These concepts are important when evaluating copyright transfer and reuse licensing agreements.
Copyright Transfer Agreement: A legal document signed by the author prior to publication that transfers all or some of the author's copyright rights to the publisher. Some rights or licenses may be returned to the author as part of this agreement. Under such an agreement, the publisher becomes the copyright holder of the work. Copyright transfer agreements are more common, and more likely to serve the interests of the publisher.
License to Publish: A legal document signed by the author prior to publication that provides the publisher with an exclusive or non-exclusive license to publish the work under additional conditions. Under a license to publish, the author retains copyright; however, the author's future use of the work may be constrained by the terms of the license. Licenses to publish are less common, but more likely to serve the interests of the author.
Pre-Print: the author's original manuscript version of a work as it was first submitted for publication. The pre-print does not include revisions made as the result of any editorial or peer-review process, nor does it include any layout or copy editing performed by the publisher.
Post-Print: The author's final manuscript version, including revisions made as the result of any editorial or peer-review process. However, unlike the published version, the post-print does not include any layout or copy editing performed by the publisher in preparation for publication. Proofs and off-prints provided to the author by the publisher do not qualify as post-prints.
Published Version: The final version of the author's work as prepared for publication by the publisher. The published version is the final print or electronic manifestation of the work, including all revisions made as the result of any editorial or peer-review process, and including any layout or copy editing performed by the publisher in preparation for publication.