Please help.

The OVDI letter ask for the "unreported income from the offshore account(s)"

In the case of a regular bank saving account, does the "income" here refer to the Interest earned from this account? Or does it refer to the Earned Income that's held in this account?

The OVDI program deals with balances maintained in overseas accounts which have NOT been reported to the IRS. These accounts must be reported annually in detail on the Report of Foreign Bank and Financial Accounts (FBAR). Additionally, this information is replicated on Form 8938 (Statement of Specified Foreign Financial Assets) that is submitted with your tax return.

On the tax return, you report the income (interest, dividends, capital gains) that your foreign accounts earn.