Exchange-traded funds (ETFs) have become very popular investments since first becoming available in the U.S. in 1993. More than $1 trillion is now invested in ETFs, which include a broad range of industry sectors covering stocks, fixed-income investments and commodities.

In this video, DailyFinance talks with Laura Morrison, head of U.S. ETF trading and listings operations at NYSE Euronext (NYX), who explains just what ETFs are, how they can best be used in an investment portfolio and how interested investors can purchase them.