Thus it has been said that humans discovered fire, rather than invented it because fire and its manufacture already existed in nature and it was up to humans eventually to perceive its significance and how it is manufactured. Matches would, however, be an invention because they are a novel combination of elements to produce fire and they are so combined by the human inventor. We also say that Columbus discovered America. This is a slightly different usage, since it really means that Europeans, or perhaps non-Scandinavian Europeans, first encountered the existence of this continent. The Amerindians had been aware of it for 30,000 or more years.
Discoveries can become inventions.
That is, presumably Ptolemus discovered that the earth was the centre of the universe, but later Copernicus and Galileo discovered a totally different relationship of earth to the universe and relegated the Ptolemaic system to being an invention. Notions of invention and discovery can both be included under the single term innovation since both entail the same essential element of combining old and existent ideas into new forms. In the case of discovery the act of innovation is a matter of first noticing the significance of some already existent combinations of items in nature. It is a common misconception to identify inventions or innovation with tools alone. The prototype of our notion of the 'inventor' is Thomas Alva Edison, a man who made the first electric light and phonograph machine.