Under federal law, if you have created an original work of authorship, such as a novel, drawing, or song, and fixed it in a tangible medium of expression (for example, wrote the work on paper, took a photograph of it, or made a recording), you probably own the copyright to the work. We say "probably" because you must have created the work and it must possess a level of originality. That means that you did not just make a list of names and put them in alphabetical order. The general categories of subject matter which may be protected by copyright include: books, articles, compositions, plays, pantomimes, dances, paintings, drawings, sculpture, films, sound recordings, buildings.
Generally, ownership of the copyright in a work belongs to the human being who initially created the work. However, if the person is an employee when he or she created the work, most likely the employer will own the copyright. This situation is known as a "work made for hire."
A "work made for hire" is a special term defined in the Copyright Act. There are two possibilities. First is a work that is created by an employee within the scope of employment. Second is a work that is specially commissioned and which falls within one of nine general categories specified in the law. These categories are: collective work, motion picture or other audiovisual work, translation, supplementary work, compilation, instructional text, test, answers to a test, atlas. In the case of a commissioned work there must also be a written agreement between the author and the entity acknowledging that it is a work made for hire.
All of the following time periods refer to works that were created on or after January 1, 1978. In the case of a work created by one human being, the copyright lasts for the life of the author plus 70 years. If more than one person was involved in the creation of a work, the copyright will last until the last of the creators has died plus 70 years. If the work is owned by a corporation or other entity because it was a "work made for hire," then the copyright exists for 95 years from its first publication, or 120 years from its first creation, whichever situation expires first.
As the law now exists, you do not need to do anything special to have a work you create be protected by copyright. However, in order to make your rights easier to establish, should there be any problems, it would probably be wise to include a notice on the work that indicates you are asserting copyright protection. Frequently such a notice appears as follows: © + year of creation + name of the owner of the copyright. By way of example: © 2015 Cheryl S. Johnson. It would also be a good idea to register the work with the U.S. Copyright Office, located in Washington, D.C. Registration within three months of publications gives you added protection if you have to sue someone for infringement of your copyright by allowing you to seek attorney fees and claim "statutory" damages, which may be easier to prove than actual damages.
In the context of copyright law, the public domain encompasses: facts, ideas, works for which copyright expired, works for which the owner has abandoned their copyright, and many federal government publications. If a work is in the public domain, it is available for anyone to use. We see countless books using classical works, like Shakespeare. No one has to ask permission or pay a fee. Likewise, people can develop derivative works based on public domain material without permission. An example of that is the musical "Westside Story" which was based on "Romeo and Juliet."
Individual words, names and short phrases (slogans) are not protected by copyright. But they may be protected by trademark law, so be careful. Titles to works are not protected by copyright but may be by laws against unfair competition if the title is strongly identified in the public's mind with the author.