With Dual Auth turned on, selected types of requested transactions or activities won't be executed or take effect until a second user's credentials are used to approve the item. The second user must be designated as an "Approver."
For example, User A creates a transfer request between two accounts. User B (previously designated as an Approver) would then log into Online Banking, and go to the Transfer Center. The transfer created by User A would show as "Pending Add Approval". User B can then select that transfer request, and then either Approve or Deny the transfer request according to their business policies.