To have adequate knowledge of a gold exchange traded fund is not common for most people, unless they know a lot about gold or invest in certain markets. On the surface a gold ETF seems complicated but to put things simply a gold ETF is a fund that has its holdings in gold, typically physical gold. They are not the safest investments in the world and when dealing with the different aspects of gold they are one of the more risky investments.
This is due to the easily fraudulent nature of the fund, it is easy for a company to say they have physical gold holdings and then they do not. If you were to buy into a gold ETF which did not have real gold backings but had previously stated it did, then the company is more likely to fold and you lose all your money. Of course their is no way for you to know if the company is technically fraudulent due to the paper work and the companies word.
You should always feel comfortable with a company before investing in them. The truth be told any company you invest in as far as shares are concerned could be fraudulent, thus they may not be any more likely to be fraudulent than any other stock company but it is something to know about in advanced. Moving on from that a gold ETF is a great way to diversify your portfolio with gold.
You do not physically own the gold but you can benefit from gold indirectly through a gold ETF. They track the spot price of gold and if the spot price goes up then you can make profits fairly easily with this plan. There are also short or inverse gold ETFs which allow you to benefit from the falling price of gold and conversely lose money when gold is doing well. There are always times when gold does well and when it falls hard and their is no way to time the market for sure, but do your homework and make wise investments.