Tax credits and tax deductions both lower your tax bill, but they work through completely different mechanisms — and understanding which is which changes how you should value them. * A tax credit reduces the actual tax you owe, dollar for dollar. A $1,000 tax credit takes exactly $1,000 off your final tax bill, no matter what tax bracket you're in. * A tax deduction works one step earlier in the process: it reduces your taxable income, not your tax bill directly. A $1,000 deduction only saves you money in proportion to your tax bracket — for someone in the 12% bracket, that $1,000 deduction lowers their actual tax bill by just $120, not $1,000. * That difference means credits are almost always more valuable than a deduction of the same dollar size, which is why lawmakers often use tax credits specifically when they want a benefit to help lower-income taxpayers as much as higher-income ones — a deduction's value grows with your tax bracket, while a credit's value stays flat regardless of income. * Credits themselves split into two types. A nonrefundable credit can reduce your tax bill all the way to zero, but no further — any leftover credit amount is simply lost. A refundable credit can push your tax liability below zero, meaning you get the excess back as an actual refund check, even if you owed no tax at all going in.