Copyright subsists for a variety of lengths in different jurisdictions. The length of the term can depend on several factors, including the type of work (e.g. musical composition or novel), whether the work has been published or not, and whether the work was created by an individual or a corporation. In most of the world, the default length of copyright is the life of the author plus either 50 or 70 years. In the United States, the term for most existing works is a fixed number of years after the date of creation or publication. In some countries (for example, the United States[44] and the United Kingdom[45]), copyrights expire at the end of the calendar year in question. The length and requirements for copyright duration are subject to change by legislation, and since the early 20th century there have been a number of adjustments made in various countries, which can make determining the duration of a given copyright somewhat difficult. For example, the United States used to require copyrights to be renewed after 28 years to stay in force, and formerly required a copyright notice upon first publication to gain coverage. In Italy and France, there were post-wartime extensions that could increase the term by approximately 6 years in Italy and up to about 14 in France. Many countries have extended the length of their copyright terms (sometimes retroactively). International treaties establish minimum terms for copyrights, but individual countries may enforce longer terms than those.[46]

Attribution (CC-BY) Attribution Share Alike (CC-BY-SA) Attribution No Derivatives (CC-BY-ND) Attribution Non-Commercial (CC-BY-NC) Attribution Non-Commercial Share Alike (CC-BY-NC-SA) Attribution Non-Commercial No Derivatives (CC-BY-NC-ND)

These licenses allow creators to communicate which rights they reserve, and which rights they waive for the benefit of recipients or other creators.

Creative Commons was invented to create a more flexible copyright model, replacing "all rights reserved" with “some rights reserved”.