
Geotagging a photo means writing a latitude and longitude into the file itself. Here are the four steps, what the photo actually stores, and the one missing field that sends a correct coordinate to the wrong hemisphere.

A photo carries three blocks of metadata and most of two of them are yours to change. Here is the working subset: each tag, what it holds, why you would touch it, and what reads it.

Windows will show a photo's location but will not let you add one, and the Mac Photos app can accept a location that never reaches the exported file. Here is what each actually does, and the browser route that avoids both.