Google Earth is a mapping product which enables users to explore any place in the world without leaving the comfort of their homes. Unlike Google Maps, Google Earth is a desktop application which allows users to view 3D images of buildings, tourist destinations, canyons of the oceans and even galaxies in outerspace!

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 And from Google itself:

Google Earth Pro builds on the amazing functionality of Google Earth with even more powerful tools. Some of the most compelling features of Earth Pro include:

• Advanced Measurements: Measure parking lots and land developments with polygon area measure, or determine affected radius with circle measure.
• High-resolution printing: Print Images up to 4800×3200 px resolution.
• Exclusive Pro data layers: Demographics, parcels, and traffic count.
• Spreadsheet Import: Ingest up to 2500 addresses at a time, assigning placemarks and style templates in bulk.
• GIS import: Visualize ESRI shapefiles (.shp) and MapInfo (.tab) files.
• Movie-Maker: Export Windows Media and Quicktime HD movies, up to 1920×1080 resolution.