In a Chapter 7 case, a creditor can object to the granting of a discharge if there is cause to do so under 11 U.S.C. § 727(a).  The creditor must timely file an adversary proceeding with the Court to object to the debtor’s discharge.  See Fed. R. Bankr. P. 4004.

Under all chapters, certain debts may be discharged unless a creditor timely files an adversary proceeding with the Court to object to dischargeability of the debt under § 523(a).  See Fed. R. Bankr. P. 4007