Marginal Tax Rate: The tax rate applied to the next dollar of taxable income earned, which increases as income rises and moves into higher tax brackets.
Progressive Tax System: A tax system where the tax rate increases as the taxable income increases, with higher incomes being taxed at a higher rate.
Taxable Income: The portion of an individual's or household's total income that is subject to income tax, after allowable deductions and credits have been applied.