TurboTax Anthony has contributed the following answer in part:
"....It summarizes ALL of the taxes you have paid either directly or through withholding on Forms such as W2s, 1099s, etc for both your federal and state returns. For example, that number would include both of your Federal and state withholding from your W2s. It can also include local taxes, refunds applied to this year's taxes from a prior year, balances due from prior years that were paid in this year, and payments made with any extension you might file.
And, while it shows under Deductions and Credits, it’s actually just a summary number and not necessarily related to any particular deduction (some of it is not even a deduction - i.e. federal taxes withheld on your federal return)."