A copyright provides its holder the right to restrict unauthorized copying and reproduction of an original expression (i.e. literary work, movie, music, painting, software, mask work, etc.) Copyright stands in contrast to other forms of intellectual property, such as patents, which grant a monopoly right to the use of an invention, because it is not a monopoly right to do something, merely a right to prevent others doing it.

The rights enforceable under copyright protection cover the use only of intangible creations - the story told within a book is protected from misuse as opposed to the printed copy itself, or the form of a sculpture as opposed to the actual carved rock.

Copyrights do not protect ideas, however, which are the domain of patents (if at all), but only the particular expression of an idea. A copyright on the cartoon character Mickey Mouse, for example, would not prevent others from creating talking mice, but only from too closely copying the character and traits of that talking mouse in particular.

Copyrights function similarly to patents, in that both grant exclusive rights over their respective subject matter that are enforceable against everyone. This is in contrast to trademark protection, which is almost always only enforceable against competitors in the same product market, and only against certain limited commercial uses.

Also in contrast to trademarks, copyright (and patent) protection is set for a limited, statutorily - defined number of years, during which the copyright owner does not actually have to make use of his work in order to keep others from doing so. After the term is up, the copyrighted work enters the public domain and is available for anyone to freely use as courts in the United States and the United Kingdom have rejected the doctrine of a common law copyright.

A copyright holder typically has exclusive rights:

• to make and sell copies of the work (including, typically, electronic copies)
• to import or export the work
• to make derivative works
• to publicly perform the work
• to sell or assign these rights to others

What is meant by the phrase "exclusive right" is that the copyright holder and only the copyright holder is allowed to do these things; everyone else is prohibited from doing them without the copyright holder's consent. Copyright is often called a "negative right", to stress that it has less to do with permitting people (e.g. authors) to do anything, and more to do with prohibiting people (e.g. readers, viewers, or listeners) from doing something: reproducing the copyrighted work.

Transfer of Rights
Copyrights may be granted, sold, or relinquished. Very often, a copyright holder will, by contract, transfer his copyrights to a corporation.

Idea-expression dichotomy
Copyright covers the expression of an idea, not the idea itself - this is called the idea-expression divide. For example, if a book is written describing a new way to organize books in a library, a reader can freely use that method without being sued and can describe it to others; it is only the particular way in which the original author described that process that is protected by copyright.

The First Sale Doctrine
Note that copyright law does not restrict resale of copies of works, provided those copies were made by or with the permission of the copyright holder. Thus it is legal, for example, to resell a book or a CD that you have purchased, provided you do not keep a copy for yourself.

How copyrights are obtained and enforced
Typically, works must meet minimal standards of originality in order to qualify for a copyright, and the copyright expires after a set period of time. Copyrights are generally enforced by the owner in a civil law court, but there are also criminal infringement statutes. Criminal sanctions are generally aimed at serious counterfeiting activity.

Copyright Notices
In general when a work such as a book or movie is registered with the appropriate country's copyright office, the material at the beginning or end may contain a copyright notice which can be a c inside a circle ©, or the word "copyright", followed by the year(s) of the copyright and the copyright owner's name. This functions to inform any potential users that the work is protected from copying.

Year(s) Of Copyright
The year(s) of copyright are listed after the © symbol. If the work has been modified (i.e., a new edition) and recopyrighted, there will be more than one year listed.