An inside cabin does not have a window, (nor a balcony for that matter <G>).
An outside cabin has a window that faces the ocean and no, the window does not open.
A Balcony cabin has a window and door that leads outside to a small porch where one may enjoy the ocean from a private area.
Steve, these are the cabins on the Voyager Class ships and what they have are bay windows that look out over the central promanade and not balconies. have been in one and it really is no big deal and you do have to be aware about keeping your curtains closed <G>