Note: JpgKeywords uses ExifTool stand-alone Windows executable (exiftool.exe). ExifTool is powerful console mode metadata reader/writer by Phil Harvey.
JpgKeywords runs ExifTool as hidden application and captures it's output, so it basically transforms ExifTool from console application to easy to use graphical application. Exiftool.exe must be present into JpgKeywords folder. It is included in JpgKeywords install, but you can always get latest version from Phil Harvey's site https://exiftool.org/