Reusing a copyright-friendly work means you don't have to receive permission from the creator, but you must still credit that source. Many sites will state how they wish to be cited, but if not you can find out how to correctly attribute the creator of the work here.
If you have a class assignment that you want to embellish with additional media--such as music, video, or pictures--there are items you can use without getting permission from the copyright holder.
There are 3 instances where you can use a work without permission:
Just remember, even if you don't need to gain permission to use the work, you still need to cite it and give credit to the copyright holder.
And of course, if you don't want to worry about possibly infringing copyright you can always exercise your own creativity and make original content!
Works in the public domain can be freely shared and reused.
Works created by an employee of the U.S. Federal Government in the scope of his or her official duties are not copyrightable and are automatically placed in the public domain. However, some works produced by government contractors may be copyrightable, and many state governments choose to protect the copyright of the works that their employees create.
When the copyright term of a work expires, that work enters the public domain. The current copyright term for most new works is the life of the creator, plus 70 more years. This is the standard term for most works published since 1978. The terms on works published before 1923 have expired and they are now in the public domain. For works created between 1923 and 1978, determining the copyright status can be a bit tricky. Peter Hirtle of Cornell University has created a chart which will help determine if a work is still under its copyright term or if it has entered the public domain. The chart is revised every year to ensure its accuracy.
Section 107 of the U.S. Copyright Law sets the standards for what constitutes the fair use of a copyrighted work. It states that fair use can include purposes such as criticism, comment, news reporting, teaching, scholarship, or research--but can also apply for many other purposes and situations. There are no explicit guidelines for what constitutes fair use. Each use must be judged on a case by case basis using the four factors stated in the law.
In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include--
(1) the purpose and character of the use;
In general, a non-commercial, educational use will be viewed more in favor of being fair use than use for a commercial venture. A transformative use (when the work is transformed into something new and is not a mere reproduction) is also more likely to be judged as fair use.
(2) the nature of the copyrighted work;
Fair use applies more to the use of published, nonfiction works and is more constrained for works of fiction.
(3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
It is more of a fair use to use less of a work, but if that small amount is the "heart" of the copyrighted work it will not be judged favorably.
(4) the effect of the use upon the potential market for or value of the copyrighted work.
Some legal commentators believe this factor to be the most important. If the proposed use of the copyrighted work will negatively impact the market for the original work it will not be viewed favorably when determining a judgement of fair use.
Creative Commons is a non-profit organization that has developed a system of free copyright licenses which allow content creators to communicate which rights they reserve, and which rights they waive. The purpose of the Creative Commons organization is to develop and support the legal and technical infrastructure of the system in order to maximize digital creativity, sharing, and innovation.
There are eleven licenses available through a combination of four conditions:
This Wikipedia article explains the licenses in more detail and also how to correctly attribute the work.
The Creative Commons website has a search function which allows you to find CC material on various websites.
The video below explains a bit more about why Creative Commons was developed.