Highlight: The very lightest color value on an object is the highlight.  Try to paint with the lightest colors and a bit of white instead of pure white.

Halftones: Any color value between the highlight and the core shadow color.  You should see a range from light halftone to middle halftone.  You can still see a good amount of detail in the halftone areas.

Core Shadow: The darkest value on an object, because it faces away from the light source.  Color and value changes are hardest to see in this area.

Reflected Light: Next to the core shadow and farthest away from the light source is reflected light.  This is light that is bouncing off of another object or surface.  Should be much weaker in intensity than the highlight.

Cast Shadow:  The shape of a shadow on an adjacent surface.  Note that the cast shadow also is made up of a core and halftones.

Shade: An area of an object that doesn’t receive any direct light.