In order to balance the interests of the creators of copyrighted works with the public's ability to benefit from those works, copyright law includes the exemption of Fair Use.
Fair use allows limited use of copyrighted material without permission for purposes such as criticism, parody, news reporting, research and scholarship, and teaching.
However, just because a use is educational does not mean that it automatically qualifies as fair use. When using content for certain purposes it is important to consider copyright and if you might be infringing on it.
Fair Use Evaluator - American Library Association
Stanford Copyright & Fair Use Center - Stanford University Libraries
Reproduction of Copyrighted Works by Educators and Librarians - U.S. Copyright Office
From the United States Copyright Office Web Site (https://www.copyright.gov/fair-use/):
Fair use is a legal doctrine that promotes freedom of expression by permitting the unlicensed use of copyright-protected works in certain circumstances. Section 107 of the Copyright Act provides the statutory framework for determining whether something is a fair use and identifies certain types of uses—such as criticism, comment, news reporting, teaching, scholarship, and research—as examples of activities that may qualify as fair use. Section 107 calls for consideration of the following four factors in evaluating a question of fair use:
In addition to the above, other factors may also be considered by a court in weighing a fair use question, depending upon the circumstances. Courts evaluate fair use claims on a case-bycase basis, and the outcome of any given case depends on a fact-specific inquiry. This means that there is no formula to ensure that a predetermined percentage or amount of a work—or specific number of words, lines, pages, copies—may be used without permission.