Why is sleep important for a healthy body?

For an adult, atleast 8 hour's sleep is essential, because during the working period throughout the day, all our nerves work and become stimulant,calories are spent to support necessary vigour. Through sleep, the human body gets the necessary rest,with nerves resting,calories reserved. As a result, in the morning after awakening from sleep, both body and mind remain fresh and motivate you to jump in your routine work schedule.