KGeoTag is a photo geotagging program.

Photos (e. g. JPEG images) contain metadata like the creation date, camera 
information etc. Those are either stored in the so-called Exif header, 
in an XMP sidecar file or in both. This data can also represent geographic 
coordinates so that it's replicable where the images were taken.

Most cameras don't have GPS receivers, so, most can't save coordinates when 
taking images. A common approach is to e. g. carry a small GPS logging device 
along, which records a track all the time. Later on, the images' dates can 
be compared to the GPS log's points' dates to figure out where an image 
was taken.

If one knows for sure where the respective photo was taken, it's also 
possible to assign coordinates to the images manually.

WWW: https://invent.kde.org/graphics/kgeotag/