Federal tax - how does it work?

[Mr. Smith]

You only have to pay more money before April 15 if you haven't paid enough taxes (through withholding) for the year or you're self-employed. Most people probably get a refund on or before April 15, and likely think that giving the government an interest-free loan of their money is a good thing. It's not.

If you didn't make anything or didn't make anything significant, you won't have to pay anything at all...but you won't get anything back either.