Google Earth first launched in 2005 as a virtual globe called Earth Viewer.
The software originated with Keyhole, a company founded in 2001 that developed a globe-based visualization program. Google acquired Keyhole in 2004 and rebranded its product as Google Earth in 2005. It combined satellite imagery, aerial photography, terrain data, and three-dimensional geographic models.
Google Earth differs from Google Maps even though the services overlap. Google Maps is primarily designed for maps, directions, local search, and navigation, while Google Earth emphasizes exploring a three-dimensional representation of the planet. Google Earth later added historical imagery, ocean information, Moon and Mars views, and user-created geographic content.
The product’s original name explains why some older references call it Earth Viewer. That name belongs to the pre-Google Keyhole software, not to a separate modern Google service.