Centers and magnifies the view in all non-camera viewports to display all visible or selected objects.
This flyout provides two functions:
Zoom Extents All: Centers and magnifies the views in all non-camera viewports so that all the visible objects in the scene are shown.
Zoom Extents All Selected: Centers and magnifies the view in all non-camera/spotlight viewports so that the selected objects in the scene are shown. If no objects are selected, the effect is the same as a normal Zoom Extents.