Sava means a corpse. In this asana you imitate a corpse.
Lie flat on you back with your arms and legs apart and eyes closed. Relax. Though it seems an easy posture it is one of the most difficult ones. While remaining motionless your mind is fully conscious and therefore relaxation in the true sense is not attained. Repeated practice enables you to keep the body still and mind relaxed.
Effect:
Yoga practices begin with Savasana and end with Savasana. The aim of this corpse posture is to obtain maximum rest for the mind and body and that too within a limited time. Savasana is good for the
health of those who suffer from hypertension and insomnia.