ETF is an acronym for Exchange Traded Fund. Just like a mutual fund, it can hold a bunch of securities in it i.e. stocks and/or bonds. Professionals agree ETF’s are vastly superior for the following reasons below

1. Costs. Mutual funds can cost between 1% - 3%. ETF’s can be as low as 0.04% or as high as 0.75%
2. Taxation. Buying a Mutual Fund makes you liable for your fellow Mutual Fund holder’s taxable transactions. For example, you plan to hold the Mutual Fund for 20 years but another Mutual Fund holder sells units today, the fund and you become liable for that transaction if it generates a tax liability. With an ETF, you are only liable for taxes if you sell.
3. Trading. You can only buy a mutual fund once a day, specifically at 4pm. With an ETF you have the open to buy anytime the market is open.

Think of it as a mutual fund 2.0.