The major difference between invention and discovery is:
invention is based on technology, whereas discovery is usually based on culture
discovery involves finding something that already exists, but invention puts things together in a new way
invention refers to material culture, whereas discovery can be material or theoretic, like laws of physics
invention is typically used to refer to international objects, whereas discovery refers to that which is local to one’s culture

   Discovery involves finding something that already exists, but invention puts things together in a new way

Explanation:  Both the invention and the discovery together make innovations. Both represent different ways or methods leading to innovation.

Discoveries related to those things, phenomena, regions, continents, planets, laws of physics that were discovered but already existed. For example, the discovery of America, it already existed before it was discovered, as well as, gravity was also there before Newton discovered it.

The inventions refers to all those innovations that were created by the formation of something new, based on an already existing one. This may be a new phone, a TV set, a car, a new scientific theory that has emerged from a combination of existing ones but throws a new light on, for example, physical theory in a way that opposes to some extent the existing ones from which it was created.