Copyright is a law that protects an author of its own work, whether it be a book, article, or video.
When looking for content to share in a classroom, there is a four part test that a teacher should look out for. The first one is make sure materials are being used non-commercially in a non profit educational institution. The second thing teachers should look out for is the nature of the work being copied. Thirdly, teachers should look for how much of the material they are using. Finally, teachers should see the effect of their use on the market.
It is important for teachers to know the differences between different types of media and their copyright laws. Each material has a different law to follow. For example, for printed material, educators can only make one copy per student. For video tapes, teachers must be able to relate it to the class content.