The "is-ought problem" is a fancy way of saying that just because something is, that doesn't necessarily mean it ought to be that way.
Think of it like this: just because it's raining outside doesn't mean you ought to stay inside all day. Maybe you really want to go outside and play in the rain, even though it might not be the most practical thing to do.
Similarly, just because something is true, that doesn't mean it's automatically good or bad. For example, it's true that some people are richer than others, but that doesn't necessarily mean it's fair or just for that to be the case.
So the is-ought problem is really just a way of reminding us that we need to think carefully about our values and priorities, and not just assume that whatever is happening is automatically the way things should be.