Time for action – using layers for controlling rendering

Layers don't just control what you can see while modeling. They also control what is rendered:

1. Press the Shift key, and hold it while you press the LMB over the layer 1 box in the Layer Visibility Control.
2. Press F12 to render the scene. Press Esc when you have seen the rendering.
3. Press Ctrl + MMB, and zoom back until you can see the lamp. Use the RMB to select the lamp.
4. Press M to get the Move To Layer menu.
5. Select Layer 5 on the menu with the LMB. Then, move the mouse away from the menu.
6. Press F12 to render the scene. Press Esc when you have seen the rendering.
7. Press the number 5. NumPad emulators select layer 5.
8. Press M and 1.
9. Press 1 and Shift + Alt + 7. NumPad emulators choose layer 1. Then, press Shift and choose layer 17.
10. Press F12 to render the scene. Press Esc when you have seen the rendering.
11. Use the RMB to select the monkey. Press X to delete it.

What just happened?

Just as the Shift key lets you select multiple objects...