Copyright
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. The exclusive rights are however balanced for public interest purposes with limitations and exceptions to the exclusive right - such as fair dealing and fair use. Copyright theory says that it is the balance between the exclusive rights and the limitations and exceptions that engenders creativity. Copyright does not protect ideas, only their expression or fixation. 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 which are covered under limitations and exceptions to copyright, such as fair use, do not require permission from the copyright owner. All other uses require permission and copyright owners can license or permanently transfer or assign their exclusive rights to others.
Initially copyright law only applied to the copying of books. Over time other uses such as translations and derivative works were made subject to copyright and copyright now covers a wide range of works, including maps, dramatic works, paintings, photographs, sound recordings, motion pictures and computer programs. The British Statute of Anne 1709, full title "An Act for the Encouragement of Learning, by vesting the Copies of Printed Books in the Authors or purchasers of such Copies, during the Times therein mentioned", was the first copyright statute.
Today copyright laws have been standardized to some extent through international and regional agreements such as the Berne Convention and the European copyright directives. Although there are consistencies among nations' copyright laws, each jurisdiction has separate and distinct laws and regulations about copyright. National copyright laws on licensing, transfer and assignment of copyright still vary greatly between countries and copyrighted works are licensed on territorial basis. Some jurisdictions also recognize moral rights of creators, such as the right to be credited for the work.
Source:
http://en.wikipedia.org/wiki/Copyright
Fair use
Fair use is a limitation and exception to the exclusive right granted by copyright law to the author of a creative work, is a doctrine in United States copyright law that allows limited use of copyrighted material without requiring permission from the rights holders. Examples of fair use include commentary, criticism, news reporting, research, teaching, library archiving and scholarship. It provides for the legal, non-licensed citation or incorporation of copyrighted material in another author's work under a four-factor balancing test. The term
fair use originated in the United States. A similar principle, fair dealing, exists in some other common law jurisdictions. Civil law jurisdictions have other limitations and exceptions to copyright.
Source:
http://en.wikipedia.org/wiki/Fair_use
Patent
A patent is a set of exclusive rights granted by a state (national government) to an inventor or their assignee for a limited period of time in exchange for a public disclosure of an invention.
The procedure for granting patents, the requirements placed on the patentee, and the extent of the exclusive rights vary widely between countries according to national laws and international agreements. Typically, however, a patent application must include one or more claims defining the invention which must be new, non-obvious, and useful or industrially applicable. In many countries, certain subject areas are excluded from patents, such as business methods and mental acts. The exclusive right granted to a patentee in most countries is the right to prevent others from making, using, selling, or distributing the patented invention without permission.
Under the World Trade Organization's (WTO) Agreement on Trade-Related Aspects of Intellectual Property Rights, patents should be available in WTO member states for any inventions, in all fields of technology,
and the term of protection available should be the minimum twenty years.
Different types of patents may have varying patent terms (i.e., durations).
Why some inventions can not be copyrights?
Because the several categories of material are generally not eligible for copyright protection, such as works that have not been fixed in a tangible form of expression.