A phone photo with GPS data
A JPEG straight off a phone often carries GPS coordinates in its EXIF data — the viewer shows the exact latitude and longitude found (such as 51.50072, -0.12462, to five decimal places), with a clear warning before you share the original file.

Do social networks keep photo metadata?
The big networks remove most metadata, including location, from the copy they show, but the original on your device keeps it. SkedCast removes EXIF and GPS data from every image before it is posted, so a scheduled post never carries a photo’s location; your originals stay in the media library for reuse.