Is it true that both layers of hair present on the animal's body are used to make wool?

Wool is a natural fibre that is obtained from animals like sheep, goats, rabbits, camels, etc. The animals have two thick layers of hair present on their bodies. The outer layer is the coarse beard hair and the inner is the soft underlayer. Soft underlayer are used to make wool as they are soft and warm. The layers help to protect the animal from the cold.