ETF pronounces as exchange-traded-fund and express a type of investment fund for investors where the cost of goods like gold, stocks and oil can be chased. So these goods can be substituted on exchanges. it will allow investors to purchase and sell their hold amound of goods for substituted offered by exchanges.
Install this app and read this one post What is ETF ? (15 July,)
https://play.google.com/store/apps/details?id=com.cryptosignals
Thanks!