A copyright is the exclusive right of use and distribution of a particular publication held by a person or organization. The right firstly lies with the creator, but the right can also have been bought from the creator or acquired through other legal constructions. Copyright is not a full or lasting claim of ownership. While it prevents other bodies from simply taking the work and distributing or adapting it on their own terms, the concept of fair use allows fragments to be used by other bodies for purposes such as reviews or descriptions. How large those fragments might be and how many may be used is a matter of relativity and estimation. The chronal limits of a copyright depend on the laws of each country, but the general rule is that one lasts until 70 years after the death of the creator or last of a team of creators. At that point, it enters public domain. Copyright and public domain are limited to the exact specifications of the original work. For instance, a certain novel might be public domain now, but younger translations in other languages might not be and distributing those translations at will might be cause for a lawsuit, while the original-language version is up for grabs. Another example might be music; while a particular piece might be taken freely after the aforementioned 70 years, a younger recording might belong to the respective artist for many years to come.
Information on copyrights in the USA can be found on the site of The United States Copyright Office. Keeping track of these websites provides insight into production developments and as to what the future may have in store for Monster High.