“A patent is an intellectual property right granted by the Government of the United States of America to an inventor ‘to exclude others from making, using, offering for sale, or selling the invention throughout the United States or importing the invention into the United States’ for a limited time in exchange for public disclosure of the invention when the patent is granted.”
(The United States Patent and Trademark Office. Inventor Resources. 16 May 2013. http://www.uspto.gov/patents/index.jsp)
Intellectual property is "property which is the product of invention or creativity, and does not exist in a tangible, physical form."
(Oxford English Dictionary, Third Edition. 2010.)
Ideas, inventions, business methods, chemical formulas, manufacturing processes, artistic expressions, and other products of human intellect and creativity are all considered forms of intellectual property.
Intellectual property is divided into four classes: patents, trademark, copyright, and trade secrets. The concept of intellectual property was established to encourage the creation of new ideas and protect those ideas and the individuals who created them.
Things that cannot be patented include:
In order to be eligible for a patent, inventions must also be:
(Information from the USPTO "Patents for Inventors" webpage.)