The section planes can be manipulated with the sectioning gizmos, available from the Sectioning Tools tab > Transform panel. You can also manipulate the section box numerically. Section planes can be moved and rotated but cannot be scaled.
By default, when a section plane is made current, the move gizmo is used, unless you have already selected the rotate gizmo before activating the section plane. All gizmos share the same location/rotation. This means that moving one gizmo affects the position of others.
You can only manipulate one plane at a time (the current plane), but it is possible to link section planes together to form slices.