http://www.iyengar-yoga.com/yogacomes this description of the Roots of Yoga
"The word Yoga comes from the Sanskrit word "Yuj" meaning to yoke, join or unite. This implies joining or integrating all aspects of the individual - body with mind and mind with soul - to achieve a happy, balanced and useful life, and spiritually, uniting the individual with the supreme.
In India, Yoga is considered one of the six branches of classical philosophy and is referred to throughout the Vedas - ancient Indian scriptures and amongst the oldest texts in existence.The Upanishads are also broadly philosophical treatises which postdate the Vedas and deal with the nature of the "soul" and universe.
However, the origins of yoga are believed to be much older than that, stemming from the oral traditions of Yogis, where knowledge of Yoga was handed down from Guru (spiritual teacher) to Sisya (spiritual student) all the way back to the originators of Yoga, "the Rishis," who first began investigation into the nature of reality and man's inner world.
Legend has it that knowledge of Yoga was first passed by Lord Shiva to his wife Parvati and from there into the lives of men."
It goes on further to say that the Aim of Yoga is
"According to the Yoga Sutras of Patanjali, the ultimate aim of Yoga is to reach "Kaivalya" (emancipation or ultimate freedom). This is the experience of one's innermost being or "soul" (the Purusa). Then one becomes free of chains of cause and effect (Karma) which tie us to continual reincarnation. In Kaivalya one is said to exist in peace and tranquillity, having attained absolute knowledge of the difference between the spiritual which is timeless, unchanging and free of sorrows, and the material which is not.
This is considered desirable as life is analysed as ultimately full of sorrows and pain- even pleasure and joy leave pain and loss when they have gone as nothing in the material world is permanent.
Yoga is therefore a spiritual quest. However, along the path of yoga, the aspirant also gains health, happiness, tranquillity and knowledge which are indicators of progress and an encouragement to continue their practice. Buddhism and other Eastern spiritual traditions use many techniques derived from Yoga."
As a yoga student and beginning practitioner I believe that it is important to understand these concepts. The history of Yoga is an integral part in the study and understanding of Yoga and for its use. How important it is for students to understand I believe lies in the hands of the student to make that choice. No matter we all practice for our own personal reasons as it is we all do what we do in general, no significant difference.
Often people ask me what type of yoga I do, what I like, what I think of styles and why I choose to practice the forms I do and here I believe is a great explanation of the forms of yoga
"Particular styles or methods may be considered more effective than others or may suit an individual's temperament better. That said, it must always be remembered that all these are merely different methods of reaching for the same ultimate goal. They are all aspects of the overall philosophy of Yoga."
Yoga is a beautiful art, a form of movement and a way to gain a health body and mind. It is what it is, now just take your time try a few different styles and classes and see what appeals to you. If it is none, then do the meditation (which is the most important aspect in my philosophy) and if anything stretch your body to keep yourself flexible, loose and less likely to incur pain or injury due to a tight, imbalanced body.
PS: Here is a link to a recent article about the various benefits of Yoga