Enthuware

I vaguely recall a question from an earlier test saying something about how a File object can never be changed once it is created.

So then how can renameTo(File newFile) work?

I'm assuming that it's similar to when you try to change a String, where you don't actually change the String but a new String is created and the reference is reassigned to that String.

That is correct. Instances of the File class are immutable but its methods can create new ones.
BTW, renameTo is not creating a new File instance. It is just renaming the physical file name. The original File object remains unchanged. You should try it out.
-Paul.