Google Earth

Google Earth is a virtual globe, map and geographic information program that was originally called Earth Viewer, and was created by Keyhole,inc, a company acquired by Google in 2004. It maps the Earth by the superimposition of images obtained from satellite Imagery, aerial photography and GSI 3D. It is available under three different licenses:

: Google Earth, a free version with limited functionality; Google Earth Plus (discontinued), which included additional features; and Google Earth Pro ($495 per year), which is intended for commercial use.

The product, re-released as Google Earth in 2005, is currently available for use on personal computers running windows 2000 and above, Mac OSX 10.3.9 and above, Linux Kernel: 2.4 or later (released on June 12, 2006), and FreeBSD. Google Earth is also available as a browser plugin (released on June 2, 2008) for Firefox3, Safari3,IE6 and IE7. It was also made available on the iPhone OS on October 27, 2008, as a free download from the App Store. In addition to releasing an updated Keyhole based client, Google also added the imagery from the Earth database to their web based mapping software. The release of Google Earth in June 2005 to the public caused a more than tenfold increase in media coverage on virtual globes between 2005 and 2006,driving public interest in geospatial technologies and applications.

Google Earth displays satellite images of varying resolution of the Earth's surface, allowing users to visually see things like cities and houses looking perpendicularly down or at an oblique angle, with perspective (see also bird's eye view). The degree of resolution available is based somewhat on the points of interest and popularity, but most land (except for some islands) is covered in at least 15 meters of resolution. Melbourne, Victoria, Las Vegas, Nevada; and cambridge, Cambridgeshire include examples of the highest resolution, at 15 cm (6 inches). Google Earth allows users to search for addresses for some countries, enter coordinates, or simply use the mouse to browse to a location.
Google Earth has the capability to show 3D buildings and structures (such as bridges), which consist of users' submissions using SketchUp, a 3D modeling program. In prior versions of Google Earth (before Version 4), 3D buildings were limited to a few cities, and had poorer rendering with no textures. Many buildings and structures from around the world now have detailed 3D structures; including (but not limited to) those in the United States, Canada, Ireland, India, Japan, United Kingdom, Germany, Pakistan and the cities, Amsterdam and Alexandria. In August 2007, Hamburg became the first city entirely shown in 3D, including textures such as facades. The Irish town of Westport was added to Google Earth in 3D on January 16, 2008. Flight simulator