This answer is one I found on the Yoga Australia website..
…As my teacher Madhuri says, “each asana (pose) not looking a certain way”. Photo: Punnamjai
There are many different ideas related to Yoga, where it comes from, what it is all about, and how to practice a range of techniques.
Generally, it is recognised as an ancient system of philosophies, principles and practices derived from the Vedic tradition of India and the Himalayas, more than 2500 years ago. It is a system that recognises the multi-dimensional nature of the human person, and primarily relates to the nature and workings of the mind, based on experiential practice and self-enquiry.
In Yoga, the body, breath and mind are seen as a union of these multi-dimensional aspects of each and every human being. The system and various techniques of Yoga cultivate the experience of that union, leading to greater integration of being, internal peacefulness, and clarity of the mind. It is a system that is designed to cultivate health and happiness, and a greater sense of self-awareness and higher consciousness.