Defination of Ayurveda:-

Ayurveda can be defined as a system, which uses the inherent principles of nature, to help maintain health in a person by keeping the individual’s body, mind and spirit in perfect equilibrium with nature.
Ayurvda is a sankrit term , made up of the words’’ayus’’ and veda.’’ “Ayus means life and “Veda” means knowledge or science. Theterm “ayurveda”thus means ‘the knowledge of life’ or ‘the science of life. According to the ancient Ayurvedic scholar Charaka, “ayu” comprises the mind, body, senses and the soul.

Ayurveda Say's :-
                                 

A healthy person , as defind in Sushrut Samhita, one of the primary works on ayurveda, is “ he whose doshas are in balance, appetite is good, all tissues of the body and all natural urges are functioning properly, and whose mind, body and spirit are cheerful….” 
The three doshas, or bio-energies found in our body are:

1. Vata pertains to air and ether elements. This energy is generally seen as the force, which directs nerve impulses, circulation, respiration, and elimination.
2. Kapha pertains to water and earth elements. Kapha is responsible for growth and protection. The mucousal lining of the stomach, and the cerebral –spinal fluid that protects the bran and spinal column are examples of Kapha.
3. Pitta pertains to fire and water elements. This dosha governs metabolism, e.g., the transformation of foods into nutrients. Pitta is also responsible for metabolism in the organ and tissue systems.