Tooth, any of the hard, resistant structures occurring on the jaws and in or around the mouth and pharynx areas of vertebrates. Teeth are used for catching and masticating food, for defense, and for other specialized purposes.
All human teeth consist of 3 main layers. The external and hardest of all layers is the enamel, underneath of enamel there is dentin, and at the center of the tooth lies the softer and live part of the tooth, the pulp.