This image is an example to help you make the transition from thinking about drawing plates and boards to drawing animal fur. As in drawing plates and boards, the value of your drawing is what gives you the illusion of fur. Darker values are down next to the animals skin. The reason is this, there's less light there. As the hair sticks up higher, it catches more light. As this layer of hair comes against the next layer of hair, the edges are created by the change in value from light to dark.
On to lesson four in how to draw fur.