Most people know what a stock is. They usually have a pretty good idea what a bond is, as well as a mutual fund, an IRA, and a portfolio. These are relatively-basic terms that fit in with adult American society even for those who aren't investors.

 An Exchange-Traded Fund, or ETF, is not very well known and even less understood, but the popularity is growing and they have an effect on people even if they aren't putting money into them. What are they? Our friends at Mint answer that question in their latest infographic.

Click to enlarge.