The thredds metadata harvester harvests the metadata from NetCDF files on the Deltares Dataportal Thredds server. It then uploads the metadata to the Deltares Dataportal Geonetwork. The script runs locally and saves ISO/TC 211 formatted XML files in the folder where you run the script from, to then upload them to the Deltares Data Portal.
The metadata harvester for Shapefiles / GeoTIFF harvests the metadata from those file types on a geoserver. It then uploads the metadata to the Deltares Dataportal Geonetwork. The script runs locally.