See the effects of rotation in different views.
The target point defines the axis of rotation for a 3D view. You can rotate a 3D view about this axis by modifying the camera level and its focal point. You can tile your project views to see the effects of the rotation in different views.
Windows panel

Camera for perspective 3D view

Camera for orthographic 3D view
The hollow blue dot is the focal point and the pink dot is the target point.