A patent is a government grant to an inventor of the right to exclude others from making, using, or selling an invention, usually for a limited period. Patents are granted for new and useful machines, manufactured products, and industrial processes and for significant improvements of existing ones. In most cases, an invention must be considered novel and useful in order to be patented. It also must represent a significant advance in the state of the art and cannot merely be an obvious change from what is already known. Patents are frequently granted for improvements of previously patented articles or processes if the requirements of patentability are otherwise met.

Source: Britannica