A patent is a set of rights granted by the federal government (or a foreign state) to an inventor (or inventors) for a fixed number of years (20 years from filing in the U.S.), which allows the inventor to exclude others from making, using, selling, offering for sale, or importing the invention claimed in the patent. A patent gives the inventor (or other patent owner, such as the assignee of the patent) the right to exclude others from making, using, selling, etc., but does not give the patent owner the right to make, use, sell, offer for sale, or import the claimed invention. The patent right is generally granted by a government as a form of monopoly to the inventor, and in return the inventor agrees that the contents of the patent will become public knowledge and will be available to the public to make, use, sell, etc. after the term of the patent expires.