The withholding would be the state tax withheld from your wages. It would be listed on line 17 (state tax withheld) or 19 (local tax withheld) on your W-2 form. Tax payments would be additional tax you paid in through estimated tax payments or from a refund from last year that you chose to have applied to this year. In other words, you need to enter the total of state and/or local taxes you have paid in for the tax year you are working on.