Copyright is a set of exclusive rights granted to the author or creator of an original work, including the right to copy, distribute and adapt the work. Copyright does not protect ideas, only their expression. In most jurisdictions copyright arises upon fixation and does not need to be registered. Copyright owners have the exclusive statutory right to exercise control over copying and other exploitation of the works for a specific period of time, after which the work is said to enter the public domain. Uses covered under limitations and exceptions to copyright, such as fair use, do not require permission from the copyright owner. All other uses require permission. Copyright owners can license or permanently transfer or assign their exclusive rights to others.