You might need to view different parts of an object at the same time. For a permanent object, you can define windows that have non-overlapping views as well as windows that have overlapping views. For a temporary object, you can define windows that have only non-overlapping views.

• A non-overlapping view means that no two windows view the same block of the object. For example, a view is non-overlapping when one window views the first and second blocks of an object and another window views the ninth and tenth blocks of the same object. Neither window views a common block.
• An overlapping view means that two or more windows view the same block of the object. For example, the view overlaps when the second window in the previous example views the second and third blocks. Both windows view a common block, the second block.