Final answer:
Patents are generally granted for 20 years and provide exclusive rights to inventors to use or sell their invention. They are granted by governments and aim to strike a balance between rewarding innovation and preventing extended monopolies.
Step-by-step explanation:
A patent is usually granted for 20 years. This time period is somewhat arbitrary, aiming to balance adequate compensation for the inventor while preventing perpetual monopoly pricing. The grant of a patent is the exclusive rights given by a government to an inventor to manufacture, use, or sell an invention for a set number of years. Patents are a form of intellectual property protection intended to encourage innovation. However, not all new ideas are eligible for a patent, and economic studies suggest that even with patent protection, inventors may only receive a fraction of the total economic value of their inventions.