A GPX file, also known as a GPS Exchange Format file, is simply a text file with geographic information such as waypoints, tracks, and routes saved in it. You can use GPX files to transfer that information between GPS units and computers.
GPX files store three types of data:
- Waypoint – are the GPS coordinates of a point. The smallest data piece.
- Track – Basically this is a list of points that describe a path.
- Route – Includes a list of track points, which are waypoints for turn or stage points, that lead to a destination.
Mapping, cycling, walking, and hiking applications combine these three sets of data (in a GPX file) to create maps and routes that users can use. There are places online where you can download GPX tracks.
Example site with great GPX resources: https://www.topografix.com/gpx_resources.asp