The main difference between the traditional and Roth IRA is their tax structure. With a Roth IRA all contributions are made from income that has already been taxed. Therefore the contributions are not tax deductible. However, the future withdrawals are all free of federal income tax. The opposite is the case with a traditional IRA where contributions to are tax deductible and future withdrawals are subject to an income tax. Traditional IRAs are usually better for taxpayers who need immediate relief, or expect to be in a lower tax bracket in retirement than during the working years.