Hi,
These two IDocs are used to post the sale transactions back in ECC from POSDM. WPUUMS IDoc will post the sales at aggregated (Summarized) level (like by article/ by club level aggregation), WPUBON IDoc will contain the sale transactions at detail level (like number of sale transactions for a given article in a given day/club).
Check the following link for more details,
Sending Data to SAP Retail - SAP POS Data Management - SAP Library
Thanks
Prakash
