Final answer:
A patent grants an inventor exclusive rights to their invention for 20 years, promoting innovation by allowing potential monopoly profits and incentivizing further research and development.
Step-by-step explanation:
The legal mechanism that grants an inventor exclusive ownership and the rights to manufacture, use, or sell their invention for 20 years is known as a patent. A patent offers protection to the inventor's intellectual property, ensuring that no other entity can profit from this invention during the patent's term without permission. The purpose of this system is to stimulate innovation by permitting inventors to potentially earn monopoly profits from their patented products, which serves as an incentive for further research and development.