Google Earth is a virtual globe program that was first called Earth Viewer and was created by Keyhole, Inc. It maps the surface of the earth by combining pictures taken by satellites and airplanes. There are also three-dimensional maps where you can look at the area from different angles. It is quite similar to Google Maps.
Google Earth is interactive, and lets the user direct the whole globe, look at satellite imagery with overlays of roads, buildings, geographic features, and more.
Teachers can use it to evaluate and strengthen students' visual literacy. Students can use it to develop a background for three-dimensional and cultural differences globally.