Every filer gets to choose one or the other β but not both. Here's how the standard deduction and itemizing actually compare, and how to tell which saves you more.
"Reduces your taxes" gets used for both β but a dollar of tax credit and a dollar of tax deduction aren't worth the same thing. Here's the actual difference.
Moving into a higher tax bracket doesn't mean all your income gets taxed at the higher rate β a misunderstanding that leads people to turn down raises or bonuses for no reason. Here's how the US federal tax bracket system actually works.