An orphan dataset is one where GBIF has been unable to access it for a long time.
A rescued dataset has been exported by GBIF into a Darwin Core Archive, to make adoption easier.
An adopted dataset has been re-published from a reliable endpoint by a publisher.
This server holds rescued datasets; that is, those that were not available from the original data provider and have been exported. See the project documentation for more information, and What is an orphan dataset? in the GBIF.org FAQ.