Sorry, but the example of Priyam is completely wrong. It is a regular inner class, not a top level nested class. And despite the comment "no outer ref. needed" it IS needed, as you can see in the main method.
A "top level nested class" is just the same as a "static inner class".
The first terminus is official and more correct since these static inner classes aren't real inner classes at all.
Do you still need an example or do you understand this already?