Both Roth and traditional have the same contribution limit of $5500. The difference is for Traditional, you fund with before tax money now and pay taxes when you take out. For Roth, you pay with after tax money now, and don't pay taxes when you take out. Both are intended for your retirement, so if you take any amount out before retirement age, you will have to pay penalty fee (10%) in addition to tax.

The benefit with both is you can save on your taxes, either now or later. Which one is best for you depends on your situation. The caveat is that your money is locked up for a long time. So if you think that your tax rate (or income) will be higher in the future (when you plan to withdraw the money- say during retirement) compared to now, Roth IRA is better. But if you think your tax rate will be lower, traditional IRA is better.

If you plan to retire early like me, you can max out on traditional IRA and 401k and later convert that to Roth IRA and avoid paying taxes now or later. If you are interested in how to do this, let me know and I can explain it to you.