The entire science of Ayurveda is based on the theory of the five great elements (Panchmahabhuta). The five elements are Ether or Space (Akash), Air (Vayu), Fire (Agni or Tej), Water (Jal) & Earth (Prithvi).
In Ayurvedic philosophy, all matter in the universe is made up of these elements: Earth represents the solid state, water the liquid, air the gaseous state, fire the transforming force and ether is simultaneously the source of all matter and the space in which it exists. Thus all matter in our bodies, from tissues and organs, to diets and "doshas" (faults) is built of these five elements.