Understanding the difference between an exchange-traded fund, or ETF, and an index fund becomes much easier once the two concepts are separated.
The key takeaway is that an index fund can be structured as either a mutual fund or an ETF, but not every ETF is an index fund. Many ETFs are actively managed, using research, quantitative models or manager discretion instead of tracking a benchmark.
So, at the end of the day, the question comes down to the difference between index mutual funds and index ETFs. Here's a look at some of their key differences.
This post originally appeared at U.S. News & World Report.