ETF: An ETF is an abbreviation for exchange-traded fund, which is an investment fund traded on stock exchanges such as the NASDAQ-100, S&P 500, Dow Jones, etc. ETFs hold assets such as stocks, commodities or bonds and they trade close to its net asset value over the course of the trading day. As one investor put it, ETFs don’t try to outperform their corresponding index. Rather, they want to replicate its performance. ETFs have been in existence since the 1980s but have risen in popularity in the last 10 years or so.
Source: NASDAQ.com and Investopedia