Life has four characteristics -- it exists, evolves, expresses and extinguishes. For this, it depends on five elements, namely earth, water, air, ether and fire. To make it easier to understand we can bring in the five senses and its objects, namely sight, smell, taste, sound and touch.
Ayurveda is the study of life. Ayur is life and Ved
means to know. According to Ayurveda, life or existence is not a rigid
compartment, but a harmonious flow. Even the five elements of which the
whole universe is made of are not tight compartments of defined
objects. They flow into one another. Each one of the elements contains
the other four.
The subtlest element in us is space, which the mind is made up of,
and the grossest is the earth element, which our bones, marrow, the skin
and the structure are made of. This is further divided into three Doshas -- Vata, Pitta and Kapha. This is a way to understand our physiology, its characteristics and its reflection on the mind.
Source - Huffington post