What a tax-advantaged retirement account actually is, how returns are made inside one, how contribution and withdrawal rules are structured, evaluating whether one is right for you, its risks, costs and taxes, and where it fits in your overall plan.
Pre-tax or post-tax is really a bet on your tax rate now versus later — The two main account structures give the same result if your tax rate is the same when you contribute and when you withdraw. The choice turns on whether you expect your rate to be higher or lower in retirement. (12 min)