According to the textbook context, 'The debit balance as per the cash book means the balance of deposits held at the bank. Such a balance will be a credit balance as per the passbook.' This is because from the business's perspective, money in the bank is an asset (shown as debit in cash book), while from the bank's perspective, the business's money is a liability (shown as credit in passbook). The context also states: 'The debit balance of the bank account as per the cash book should be equal to the credit balance of the account of the business in the books of the bank.'