Copyright

A copyright is a type of intellectual property that gives its owner the exclusive right to copy, distribute, adapt, display, and perform a creative work, usually for a limited time. The creative work may be in a literary, artistic, educational, or musical form. Copyright is intended to protect the original expression of an idea in the form of a creative work, but not the idea itself. A copyright is subject to limitations based on public interest considerations, such as the fair use doctrine in several countries.

Some jurisdictions require "fixing" copyrighted works in a tangible form. It is often shared among multiple authors, each of whom holds a set of rights to use or license the work, and who are commonly referred to as rights holders. These rights frequently include reproduction, control over derivative works, distribution, public performance, and moral rights such as attribution.

Copyrights can be granted by public law and are in that case considered "territorial rights". This means that copyrights granted by the law of a certain state do not extend beyond the territory of that specific jurisdiction. Copyrights of this type vary by country; many countries, and sometimes a large group of countries, have made agreements with other countries on procedures applicable when works "cross" national borders or national rights are inconsistent.

Typically, the public law duration of a copyright expires 50 to 100 years after the creator dies, depending on the jurisdiction. Some countries require certain copyright formalities to establishing copyright, others recognize copyright in any completed work, without a formal registration. When the copyright of a work expires, it enters the public domain.

Fair use
There is an exception to the rules of copyright, called fair use. This means that people can copy a very small amount of a work to use in reviews or in research reports.

An example of fair use is when newspaper writers quote several sentences from a copyright-protected document to tell the story. Another example of "fair use" is when a university professor quotes several sentences from a copyright-protected book in a review of the book, or in a research report.

Copyright in different countries
Different countries have different copyright laws. Most of the differences are about: Because of these differences, a certain piece of work may be under copyright in one country, and in the public domain in another.
 * whether or not the government's work falls under copyright,
 * how much longer copyright lasts after the author dies or after the work is created or published, and
 * what is and what is not fair use.