According to the U.S. Copyright Office, "copyright is a form of protection grounded in the U.S. Constitution and granted by law for original works of authorship fixed in a tangible medium of expression. Copyright covers both published and unpublished works." (https://www.copyright.gov/)
Literary Works such as children's books, short stories, novels, speeches, textbooks, workbooks, manuscripts, etc.
Musical Works including accompanying music such as songs, sheet music, lyrics, spoken word, etc. It doesn't matter whether the format is a CD, LP, MP3 or any other version, it is still copyrighted.
Dramatic Works including accompanying music such as plays, television scripts, etc.
Pantomimes and choreographic works including choreographic skits, dance movement and patterns.
pictorial, graphic, and sculptural works such as art work, photos, graphics, cartoons, logos, etc.
motion pictures and other audiovisual works such as movies, television shows, online digital videos, etc.
sound recordings including a recorded performance that does not include television, movies, or other audiovisual work.
architectural works including design of a building including the plans and accompanied drawings.
(https://www.copyright.gov/)
Fair Use is a legal doctrine in law that grants a person or organization in the United States limited use of copyright material without having to first acquire permission.
The Fair Use Doctrine ( 17 U.S. Code § 107,) provides guidelines to follow when copyrighted materials can be used.
You must be aware of when you can use work without permission and when you can not.
Copyrighted works can be used if it falls under the following Fair Use Guidelines:
the purpose and character of the use, including whether it is of a commercial nature or for nonprofit educational purposes
You can use copyrighted work for teaching or instructional purposes but you still must respect the wishes of the person or company holding the copyright. You can not infringe of the copyright holder from benefiting or profiting on their own work. For example, it is okay to hand out copies of a short poem to students in class to read but it is not okay to post the poem on a website or public social site for students and the general public to access. The only exception is for materials in the public domain.
the nature of the copyrighted work
You should make sure the work is informational in nature. This will help determine whether the use will fall under Fair Use Doctrine or not. Copying from works that are scholarly, scientific, or in the daily news can be used as it encourages the free spread of ideas and benefits the public. However, you should determine the work has already been published and still properly cite your sources.
the amount of the portion used in relation to the copyrighted work as a whole, and
In the court system, the judge will often consider the amount of work that has been copyrighted. There is no rule of law rather a good guideline to consider is whether the work being used is substantial or not. For example, if a song is over 5 minutes long and you want to sample 1 minute, it may fall under fair use. But if you want to sample 3 minutes of the same song, that would be breaking copyright laws.
the effect of the use upon the potential market for or value of the copyrighted work.
The fourth, and in some people's opinion the most important, is to consider the effect using the material could have on the person who actually created it. For example, if you take a picture from a famous photographer and reproduce it as an artistic rendering, does that take away the value from the person who took the original picture? In this case, it would and you would be breaking copyright. What about reading a children's book on youtube? Would that have a negative impact on the author and illustrator who created the work? Yes. Again, you would be breaking copyright as it would negatively affect the author and illustrator collecting money from sales of the book.
(https://www.nolo.com/legal-encyclopedia/fair-use-the-four-factors.html)