ETFs are exchange traded funds. They are investment vehicles that involve a basket of assets, that can include stocks and bonds. Like mutual funds, ETFs can be created to track specific indices (such as tech or agriculture).
Unlike mutual funds, which can only be traded once per day, ETFs can be bought and sold throughout the day in the same manner as individual stock.
In episode 28 of the Spondulix podcast, I get into the details of ETFs. Take a listen below.