Up till now, you've just changed your view of the scene. Now it's time to alter it. You'll move the lamp and see how that affects the cube:
To start, either open Blender or select New. You will see the familiar 3D View.
Press F12 to render the scene.
Observe how the cube looks.
Press the Esc button to close the render window.
Put the cursor over the lamp. Hold theRMB down and begin to drag the mouse. When the lamp begins to move, you may release theRMB. Move the lamp to the left so it is between the camera and the cube. Press theLMB to release the object. If you press theRMB again, it will cancel the movement.
Press F12 to render the scene.
Observe how the cube looks. The left side is much lighter as you can see here.
Press the Esc button to close the render window.