Fair use

Fair use

Fair use is a doctrine in United States copyright law that allows limited use of copyrighted material without requiring permission from the rights holders, such as use for scholarship or review. It provides for the legal, non-licensed citation or incorporation of copyrighted material in another author's work under a four-factor balancing test. The term "fair use" originated in the United States, but has been added to Israeli and the UK law as well; a similar principle, fair dealing, exists in some other common law jurisdictions. Civil law jurisdictions have other limitations and exceptions to copyright.

http://en.wikipedia.org/wiki/Fair_use