If you buy a share of an ETF @ 60 and sell at 62, you will have a $2 cap gain and pay cap gains tax on that gain.
If you buy a share of a fund @ 60 and sell at 62, you will have a $2 cap gain and pay cap gains tax on that gain.
Thus, there is no difference between a share of the ETF and the share of the mutual fund as far as this transaction is concerned.
You also need to know that there are various cap gains tax rates. Some folks will pay 0% rate, some 15% rate, some a marginal income tax rate, and some other rates. One needs to understand how capital gains are taxed. In particular, presently short-term capital gains are taxed as ordinary income, so one would pay marginal income tax rates on the gain, which could be 0% or could be 28%, 33%, or some other rate. Long-term capital gains are taxed somewhat differently, but generally at a lower rate than short-term cap gains. Thus, it pays to avoid short-term cap gains and only incur necessary long-term cap gains. And one needs to know that unrealized cap gains are not taxed.
As citizens of the US where we vote for reps who make tax laws for us, we all have the obligation to understand how we are taxed, so it is great that you are learning about all this.
It's all about market timing, uh, I mean rebalancing, uh, I mean opportunistic rebalancing, uh, I mean short-term opportunistic rebalancing due to a short-term change in one's asset allocation.