What is "Fair Use" ??

Fair use, originated in the USA, is a method of legally using copyrighted work. To simplify, it means that you can use the other's work without prior permission. The use must be narrowed down. It can not be as same as the original owner of that work. It allows you to copy some of the work and uses it to fulfill your target. Categorizing it into 2 kinds, the first is "comment and criticize(review)," the second on is parody. You can quote your favorite lines from the Avengers in your movie review. Furthermore, you can also make a joke on some scenes. This kind of joke which involving copyrighted work is called parody. All of these action above is considered as a "fair use" and it is not a copyrighted violation.