In plain terms, the difference is about the timing of the tax. One type is generally funded with money you haven't been taxed on yet, with tax handled later; the other is funded with money you've already paid tax on, with different treatment down the road. Which one fits you depends on your own situation, and that's a conversation with your CPA — not a web-page answer.
Two Different Timings
Both are retirement account types with rules set by tax law. The cleanest way to hold the difference in your head is that they don't apply the tax at the same point in the journey.
That single difference is what drives most of the comparison people argue about online.
Why There Is No Universal Answer
Which timing works out better for a given household depends on things nobody can know from the outside — your situation now, your situation later, what else you've got, and rules that change over time.
You'll find plenty of confident takes about which one is better. Be careful with them. Confidence about your money from somebody who has never seen your numbers isn't worth much.
Deliberately No Figures Here
We don't publish limits, thresholds or projections on this page. Those are set by tax law, they move, and getting them slightly wrong in either direction can cost you real money.
Your CPA can tell you what applies to you this year. If you want help thinking about how the pieces fit together, that's what a sit-down is for.
Want a Straight Answer for Your Own Situation?
Thirty minutes, no pitch, no obligation — just a plain look at where you stand.