Operating Profit (EBITDA) % is your net profit before interest, tax, depreciation and amortisation for the current period.
If you select a finalised month (see red square above) that isn't the financial year end then the figures will be annualised for the current financial period.
The little coloured number in the lefthand corner is the percentage points difference in the operating profit (EBITDA) % between now and the previous financial year.