A patent for an invention is a grant of a property right by the US Government to the inventor or his or her heirs or assigns.

In the United States, there are three types of patents.

1. By far, the most common is what is called a "utility" patent which can be obtained for any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvements thereof.
2. Another U.S. patent is a "design" patent which is directed to any new, original and ornamental design for an article of manufacture. A design patent is thus for how something looks, not for its utility or how it works.
3. Finally, there is a U.S. "plant" patent that is directed to inventions or discoveries of asexually reproduced distinct and new varieties of plants, including cultivated sports, mutants, hybrids and newly found seedlings (but not tuber progated plants or plants found in uncultivated states).

    The terms of a utility patent and a plant patent are twenty (20) years from their effective filing dates. A design patent's term is fourteen (14) years from its issuance date.

    Rights conferred by a patent grant extend throughout the United States, its territories and possessions. The grant of a patent provides the owner with the right to exclude others from making, using, offering for sale or selling the invention in the United States or importing the invention into the United States.

    Each country has its own statutes and regulations relating to patents. These are, of course, amended from time to time. Generally speaking, the scope of patent coverage and terms of patents in foreign countries and the U.S. are similar. Nevertheless, they do vary. Texts which are updated annually are available which describe patents in individual countries. For precise and complete information, patent attorneys and agents in the countries involved should be consulted.

    There are three patent applications which are never more than applications, these are (1) a U.S. Provisional Application, (2) an International Patent Application, and (3) a European Patent Application. A Provisional Application must contain an adequate description of the invention, but need not have other parts of a conventional patent application such as an Abstract, Background of the Invention, and Claims. To obtain a U.S. Patent, it must be superseded by a conventional application within one year of its filing date. An International Patent Application is usually filed within one year of, and is essentially the same as, a national application. It extends the time for filing corresponding foreign applications twenty (20) months (or in some cases thirty (30) months) from the filing date of the basic national application. A European Patent Application is much the same as an International Patent Application, except that it is limited to members of the European Union. However, unlike an International Patent Application, corresponding applications in European Union countries are generally not examined for patentability, whereby obtaining national patents based upon European Patent Applications is generally more or less pro forma.