A patent is a grant of a property right by the Government to the inventor in exchange for disclosing a patentable invention. A patent does not grant the inventor the right to make, use, or sell the invention, but does grant the right to exclude others from making, using, or selling the invention. Patents are granted for a term of 20 years from the date of filing the original application, (14 years for design patents) which may be extended only by a special act of Congress. After expiration of the term, the patentee loses rights to the invention.
Some persons occasionally confuse patents, copyrights, and trademarks. A trademark protects a word, phrase, symbol or design which indicates the source or origin of goods; a copyright protects the form of expression rather than the subject matter of the writing.