e/Backup Domain Controller

Information
has gloss	eng: In Windows NT 4 server domains, the Backup Domain Controller (BDC) is a computer that has a copy of the user accounts database. Unlike the accounts database on the Primary Domain Controller (PDC), the BDC database is a read only copy. When changes are made to the master accounts database on the PDC, the PDC pushes the updates down to the BDCs.
lexicalization	eng: Backup Domain Controller
instance of	e/Identity management systems