Key light: the brightest and main source of light of your subject Generally positioned about 45 degree angle from the camera.

Fill light: Fills in the shadows created by the key light. Positioned on the other side of the camera from the key light, illuminating the shadows cast from the key light. Must be less bright than the key light, so there is still contrast on each side of the subject.

Backlight: Creates a rim of light around the subject to distinguish the subject from the background. Positioned behind the subject