What is not protected by copyright?
Several categories of material are generally not eligible for federal copyright protection. These include among others:
Works that have not been fixed in a tangible form of expression (for example, choreographic works that have not been notated or recorded, or improvisational speeches or performances that have not been written or recorded)
Titles, names, short phrases, and slogans; familiar symbols or designs; mere variations of typographic ornamentation, lettering, or coloring; mere listings of ingredients or contents
Ideas, procedures, methods, systems, processes, concepts, principles, discoveries, or devices, as distinguished from a description, explanation, or illustration
Works consisting entirely of information that is common property and containing no original authorship (for example: standard calendars, height and weight charts, tape measures and rulers, and lists or tables taken from public documents or other common sources).
Here is a August 5, 2015 announcement from Reed Library of Copyright Law and the use of online textbooks.
Does copyright protect an author's creative ideas?
No. Copyright shelters only fixed, original and creative expression, not the ideas or facts upon which the expression is based. For example, copyright may protect a particular song, novel or computer game about a romance in space, but it cannot protect the underlying idea of having a love affair among the stars. Allowing authors to monopolize their ideas would thwart the underlying purpose of copyright law, which is to encourage people to create new work.
For similar reasons, copyright does not protect facts -- whether scientific, historical, biographical or news of the day. Any facts that an author discovers in the course of research are in the public domain, free to all. For instance, anyone is free to use information included in a book about how the brain works, an article about the life and times of Neanderthals or a TV documentary about the childhood of President Clinton -- provided that that they express the information in their own words.
Facts are not protected even if the author spends considerable time and effort discovering things that were previously unknown. For example, the author of the book on Neanderthals takes ten years to gather all the necessary materials and information for her work. At great expense, she travels to hundreds of museums and excavations around the world. But after the book is published, any reader is free to use the results of this ten year research project to write his or her own book on Neanderthals -- without paying the original author.
When can I use a work without the author's permission?
When a work becomes available for use without permission from a copyright owner, it is said to be "in the public domain." Most works enter the public domain because their copyrights have expired.
To determine whether a work is in the public domain and available for use without the author's permission, you first have to find out when it was published. Then apply the following rules to see if the copyright has expired:
All works published in the United States before 1923 are in the public domain.
Works published after 1922, but before 1978 are protected for 95 years from the date of publication. If the work was created, but not published, before 1978, the copyright lasts for the life of the author plus 70 years. However, even if the author died over 70 years ago, the copyright in an unpublished work lasts until December 31, 2002.
For works published after 1977, the copyright lasts for the life of the author plus 70 years. However, if the work is a work for hire (that is, the work is done in the course of employment or has been specifically commissioned) or is published anonymously or under a pseudonym, the copyright lasts between 95 and 120 years, depending on the date the work is published.
Lastly, if the work was published between 1923 and 1963, you must check with the U.S. Copyright Office to see whether the copyright was properly renewed. If the author failed to renew the copyright, the work has fallen into the public domain and you may use it.
The Copyright Office will check renewal information for you, at a charge of $20 per hour. (Call the Reference & Bibliography Section at 202-707-6850 202-707-6850.) You can also hire a private copyright search firm to see if a renewal was filed. Finally, you may be able to conduct a renewal search yourself. The renewal records for works published from 1950 to the present are available online at https://www.copyright.gov/. Renewal searches for earlier works can be conducted at the Copyright Office in Washington D.C. or by visiting one of the many government depository libraries throughout the country. Call the Copyright Office for more information.
With one important exception, you should assume that every work is protected by copyright unless you can establish that it is not. As mentioned above, you can't rely on the presence or absence of a copyright notice (©) to make this determination, because a notice is not required for works published after March 1, 1989. And even for works published before 1989, the absence of a copyright notice may not affect the validity of the copyright -- for example, if the author made diligent attempts to correct the situation.
The exception is for materials put to work under the "fair use rule." This rule recognizes that society can often benefit from the unauthorized use of copyrighted materials when the purpose of the use serves the ends of scholarship, education or an informed public. For example, scholars must be free to quote from their research resources in order to comment on the material. To strike a balance between the needs of a public to be well-informed and the rights of copyright owners to profit from their creativity, Congress passed a law authorizing the use of copyrighted materials in certain circumstances deemed to be "fair" -- even if the copyright owner doesn't give permission.
Often, it's difficult to know whether a court will consider a proposed use to be fair. The fair use statute requires the courts to consider the following questions in deciding this issue:
Is it a competitive use? (In other words, if the use potentially affects the sales of the copied material, it's usually not fair.)
How much material was taken compared to the entire work of which the material was a part? (The more someone takes, the less likely it is that the use is fair.)
How was the material used? It is a transformative use? (If the material was used to help create something new, it is more likely to be considered a fair use than if it is merely copied verbatim into another work. Criticism, comment, news reporting, research, scholarship and non-profit educational uses are most likely to be judged fair uses. Uses motivated primarily by a desire for a commercial gain are less likely to be fair use.
As a general rule, if you are using a small portion of somebody else's work in a non-competitive way and the purpose for your use is to benefit the public, you're on pretty safe ground. On the other hand, if you take large portions of someone else's expression for your own purely commercial reasons, the rule usually won't apply.
What are the exceptions to the rule that the creator of a work owns the copyright?
Copyrights are generally owned by the people who create the works of expression, with some important exceptions:
If a work is created by an employee in the course of his or her employment, the employer owns the copyright.
If the work is created by an independent contractor and the independent contractor signs a written agreement stating that the work shall be "made for hire," the commissioning person or organization owns the copyright only if the work is (1) a part of a larger literary work, such as an article in a magazine or a poem or story in an anthology; (2) part of a motion picture or other audiovisual work, such as a screenplay; (3) a translation; (4) a supplementary work such as an afterword, an introduction, chart, editorial note, bibliography, appendix or index; (5) a compilation; (6) an instructional text; (7) a test or answer material for a test; or (8) an atlas. Works that don't fall within one of these eight categories constitute works made for hire only if created by an employee within the scope of his or her employment.
If the creator has sold the entire copyright, the purchasing business or person becomes the copyright owner.
Source: Stanford University, http://fairuse.stanford.edu/Copyright_and_Fair_Use_Overview/chapter0/0-a.html#1