The term Asana literally means “sitting position” or simply “position”: it points out a bodily posture that contributes to the physical and mental stability and it generates a sense of comfort.
The term Asana is also used to point out a vegetable mat, or also a skin of well tanned antelope, which is a comfortable support to sit on the ground. In hatha-yoga the Asanas occupy a primary place, while they represent the third step in the eightfold yoga of Patanjali (astanga).
Usually the term Asana is translated with the word “position”: we find therefore expressions as “position of the cobra”, “position of the crocodile”, “position of the arc”, and so on. It is true that many Asanas consist of a particular posture: nevertheless the Asanas differ from the simple positions in many aspects, therefore the term “position” doesn’t explain completely the meaning of the term Asana.
In a “position”, even if this is maintained in an economic way, without great effort, there is no consideration of the mental attitude: this can vary in different positions. We comfortably relax, for instance sitting in an armchair, yet, in that though comforting position it can happen that we are mentally upset because of particular connections of thoughts.
Many bodily positions are assumed and maintained by the nervous system, under the level of consciousness, that is, without the interference of attention. This happens, for instance, when a sitting position is assumed for writing, or a standing position. An Asana is at first voluntarily assumed, then it can be maintained, but the activity of maintenance and control develops under the level of consciousness.
The thought process is not allowed during the practice of Asana: a particular kind of awareness is recommended during the maintenance of the Asana (for instance the awareness of breath), so that there are no interferences due to mental activity. Any further movement (except that necessary for the attainment of the Asana) is imposed to the body, and also the movement to assume the Asana and to leave it is achieved in a particular way, slowly and harmoniously.
The movements to assume an ordinary bodily position are not so important and can be achieved in whatever way. The ordinary positions as standing, sitting, or lying down, don’t constitute a special exercise for the muscles and involved nerves. On the contrary in the Asana a specific training is requested on the physical plane and on the mental plane. Besides, the ordinary positions can be maintained with the help of an external support (for instance sitting on a chair): the Asana doesn’t ask for some support (with the exception of the ground).