If you did not pay enough estimated taxes and/or you did not have enough taxes withheld from your wages, then your total tax payment will be less than your total tax liability and you will have taxes owed.
Your taxes owed will be on your federal tax return, Form 1040, on Line 37. Any Underpayment Tax Penalty will be on Line 38 and the amount on Line 38 will be included in the amount on Line 37.