In the United States, three basic types of patents may be obtained. The great majority of patens are so-called "utility patents." These patents are directed to machines, processes, articles of manufacture or compositions of matter, life forms or any new and useful improvements thereon. The term of a utility patent runs twenty (20) years from the date of filing, and at the end of this period, the invention become public property and can be used by anyone without legal restraints. After the issuance of a patent, separate maintenance fees must be paid at intervals of 3 years, 7 years, and 11 years after the issue date in order to keep the patent in full force and effect.

The second type of patent is termed a "plant patent." A plant patent is granted by the government to an inventor who has developed an asexually reproduced, variety of plant other than a tuber propagated plant or a plant found in an uncultivated state. The term of this patent is also twenty (20) years from the date of filing.

The third type of patent is a design patent. Unlike the previously mentioned patents, it does not have to be useful; but merely must be novel and ornamental. Ornamental means that the invention must be the product of aesthetic skill and artistic conception. If the design of the invention is basically functional (that is, calculated to serve a useful purpose) the n the inventor should obtain a utility patent rather than a design patent. However, an item which is functional may still have an ornamental aspects and this aspect is subject to protection under a design patent provided that its appearance is not dictated solely by functional considerations. A design patent is obtained for fourteen (14) years from issue.