Zooming in or out of the view without changing the angle of the scene viewpoint. Zooming is always available when in Orbit or Panning mode.
Mouse Control: In Orbit mode and Panning mode, zooming is always available by rolling the scroll wheel forward to Zoom in and backward to scroll out.
Panning moves the scene right, left, up, or down without changing the orientation or distance.
Mouse Control: In Orbit mode, Panning is always available by holding down the left mouse button and dragging right, left, up, or down.