FWIW I've heard both used interchangeably (in banking, adtech, and other tech verticals).
Edit: the linked wikipedia articles discriminate the terms by defining SSOT as a single place to store and edit every data element, while SOR allows for replicas, but in the case of data discrepancies, the SOR's state wins.
Edit: the linked wikipedia articles discriminate the terms by defining SSOT as a single place to store and edit every data element, while SOR allows for replicas, but in the case of data discrepancies, the SOR's state wins.