<networking> (BDC) A server in a network of Microsoft Windows computers that maintains a copy of the SAM database and handles access requests that the Primary Domain Controller (PDC) doesn't respond to. There may be zero or more BDCs in a network. They increase reliability and reduce load on the PDC.
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Nearby terms: backtick « backtracking « backup « Backup Domain Controller » backup pumpkin » backup rotation » backup software