Resell Rights
As you are no doubt aware it is generally the case in most countries (including the United States) that the author of a work owns the copyright in that work. There are couple of exceptions - authors do have the right to assign their copyrights to others, for example they might sell their copyright to somebody else, and in the case of a person creating a work as part of their job function, the work is usually known as a “work for hire” and the copyright assigned to the author’s function.
In any case, whoever owns the copyright in a particular work, they do have certain exclusive rights as a result of copyright law. These include the exclusive right to copy the work, or to authorize others to do so. In other words, that means that unless you have permission from the copyright holder, you’re infringing their copyright if you copy or distribute the work.
However there are situations where you may be able to get permission from a copyright holder to copy or distribute their work, and perhaps even sell copies of the work and keep all the money for yourself. In these situations the copyright holder grants you want is known as “resell rights” (also sometimes called “resale rights”) - the right to resell the product. You may also encounter situations where the copyright holder grants you the right to grant others resell rights, this is usually known as “master resell rights”.
Resell rights are most commonly available for eBooks and reports, but you may also run across them for other types of products, including software, as well as video and audio products.
Why would an author give out resell or master resell rights? There are many possible reasons. Some authors for example sell these rights in order to earn extra cash. Other authors are not trying to earn money by selling the rights, but instead want their work as widely circulated as possible (perhaps because the work contains advertising or affiliate program links). I’ve even encountered authors who were trying to build a large opt-in mailing list, and were prepared to give resell rights to anybody who subscribed to their email newsletter!
The quality of resell rights products varies widely - there are both good and bad products available, so you do need to select carefully. You should also be aware that “resell rights” and “master resell rights” are not legal terms - exactly what you are allowed to do with any particular product will depend on what that product’s copyright holder’s terms and conditions state.