(from the USPTO publication General Information Concerning Patents)
A patent for an invention is the grant of a property right to the inventor issued by the United States Patent and Trademark Office. U.S. patent grants are effective only within the United States, U.S. territories, and U.S. possessions. Under certain circumstances, patent term extensions or adjustments may be available. The right conferred by the patent grant is, in the language of the statute and of the grant itself, "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. What is granted is not the right to make, use, offer for sale, sell or import, but the right to exclude others from making, using, offering for sale, selling or importing the invention. Once a patent is issued, the patentee must enforce the patent without aid of the USPTO.
There are three types of patents:
For more information, please refer to the complete General Information concerning Patents at the USPTO website. For information about Utility Patents, see A Guide to Filing a Utility Patent Application. For more information about Design Patents, see A Guide to Filing a Design Patent Application. For more information about Plant Patents, see General Information about Plant Patents.