Currently I have a Trad IRA with equities valued at 16,000 and a 401k saving. I would like to invest in a Roth IRA and would like some information such as

What is a ROTH IRA and how is it different from a Traditional IRA?

How can I benefit from investing in a Roth IRA?

What kinds of investments should I have in a Roth IRA?

What does it mean to covert and unconvert?

Thanks!