There is another way to move an object, which you will explore now. Notice the change in how the cube looks when you move the lamp close to the camera:
Press the 1 key on the NumPad to get the Front view.
Press the Home key. On a Mac without a Home key, press the fn and left arrow key. This will show you all the objects in the scene.
Check in the upper-left corner of the 3D View window to make sure that you are in the Front Ortho view. If it says Front Persp, press the 5 key on the NumPad to get the orthographic view.
Observe the red and blue arrows that stick out of the lamp.
Put the cursor over the blue arrowhead. Hold the LMB down and move the lamp up until it is in level with the camera, as shown in the left section of the following screenshot. Note that when you select the arrowhead, the arrows disappear and are replaced by a line that shows you the direction you can move in. Release the LMB when it's in level with the center of the camera.
Press...