Explanation: The storage selector act as a layer between RMAN, which accesses the database, and the Oracle Secure Backup software, which manages the backup media. For backups, Oracle Secure Backup stores metadata about RMAN backup pieces in the Oracle Secure Backup catalog. The Oracle Secure Backup catalog is stored and managed completely separately from the RMAN recovery catalog. Oracle Secure Backup stores each backup piece and corresponding metadata about the piece. References: https://docs.oracle.com/cd/E16926_01/doc.121/e16564/osb_rman_backup.htm