<prompt> Human: Hey. I am starting to take my retirement savings pretty seriously. I have a 401k and it is growing nicely. I know there is an IRA or Roth IRA thing. I know that money can be rolled over into them. But I REALLY dont understand what it means, why I should, or how to go about it. The information I find online seems to presuppose a lot of information on the subject.Can anyone help, please?  <response>: ELI5: How does an IRA work? 