The edit control is displayed when you click on a scene component.
Clicking on an axis and dragging results in the object rotating around its origin using the axis selected. Holding down the shift key while dragging results in the scene being rotated around the active object's origin.
Clicking on one of the light grey planes that represent the XZ or YZ axis and dragging results in object, face(s) or point(s) being moved along the selected plane.
Clicking on one of the dark grey planes that represent the XZ or YZ axis and dragging results in the object being scaled along the selected plane. Holding down the shift key while dragging results in equal scaling of the object in all directions. In the case of a light, scaling results in the intensity of the light being scaled.
Note that scaling and rotation does not apply to selected faces or points.