GPS Exchange Format File
The United States Military created a navigational system that uses 24 satellites for geographical use and pinpointing a position anywhere hence the name Global Positioning System or as it is usually know GPS.
These satellites are also used for non military purposes such a navigating or geocaching.
For the non military uses files that use the extension .gpx are used this means Global Positioning Exchange file and acts as a marker to show that the file works together with navigation programs.
Regardless of whether Software or computers or GPS devices are used the .gpx file is used to transfer the necessary information needed.
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How to open .gpx files?
Software to open .gpx files
What are .gpx files