Expression and underlying ideas
Books, music, photographs, films and computer programs can receive protection. Copyright concerns expression rather than ownership of ideas, operating methods or mathematical concepts as such. Particular wording and the facts it discusses are distinguishable.
Eligibility follows national rules. In the United States, originality and fixation are central conditions. Such formulations need their jurisdictional context rather than being assumed to describe every legal system identically.
Economic uses and authorship interests
Economic rights cover uses including reproduction, performance, broadcasting, translation and adaptation. Moral rights recognized in many systems protect interests such as claiming authorship and opposing reputation-damaging alterations.
The creator and economic-rights owner need not always coincide. Employment rules, assignments and inheritance can affect ownership, as the U.S. Copyright Office explains for its jurisdiction. Licensing a use also differs from transferring ownership.
Automatic protection and permitted use
Berne protection generally does not depend on registration, although voluntary national systems can have evidentiary or procedural effects. Absence of registration therefore does not by itself establish absence of copyright.
Uses can be authorized by licences or permitted by statutory exceptions. Expiry raises public-domain questions. Online publication does not automatically remove protection, and free access is distinct from unrestricted copying or redistribution.