system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is a Roth IRA?
gpt
It's an investment account designed for retirement. You pay money into it and use that money to invest in things like mutual funds. Upon retirement age, you may pull out the money with any interest without paying taxes on it. Also, since you put in already-taxed dollars, you're allowed to withdraw up to what you put in at any time without any tax penalty.

It complements a 401k plan, in which you aren't taxed on what you put in but are taxed on what is pulled out. By using a Roth IRA and a 401k, you can manage your tax liability now and during retirement.