Final answer:
A patent is a government rule that gives the inventor exclusive rights to their invention for a certain number of years, typically 20 years.
Step-by-step explanation:
A patent is a government rule that gives the inventor the exclusive legal right to make, use, or sell their invention for a certain number of years.
In the context of this question, patents granted by the federal government are typically valid for a period of 20 years. This means that the inventor has the exclusive rights to their invention for those 20 years, after which the patent expires and the invention enters the public domain.