The 3-Point Lighting technique has been used for ages by studio photographers to create portrait shots.

You usually need three lights.

- A Key Light. The strongest light and sets the lighting of the scene
- A Fill Light. Helps to fill the shadows where the main light can’t reach
- A Back Light. Lights from the back to enhance separation.

The folks at MediaCollege have created a very nice explanation of this three light technique, as well as a cool demo that allows you to see the effect of specific lights by clicking on them to turn off.