An inventor, in the context of a patent application, is an individual who has contributed to the conception of at least one claim in the patent. This person must have played a significant role in the development of the inventive concept covered by the patent claims. To be listed as an inventor on a patent application, the individual must have made a creative contribution to the invention's innovative aspects, rather than merely executing or following instructions. Their inventive input must be substantial enough to influence the patentable elements of the invention.