I think it is easy. we may have to tell them that these are all forks and since they had to be used somewhere we named them and assigned them different purposes.
Even after that there will still be a question. We may have to explain them what is a fork?
Thus i think the only solution for this problem is time. With time they will learn everything. Instead of putting all our energy in thinking what different steems are, i think we should concentrate on posting good quality content.