Yoga is generally understood as a process of unification. This unification is multifaceted. In one dimension, it is a unification of the various systems that exist within the human being including the emotional, physical, mental, and spiritual systems. In total there are believed to be five different systems within human life. These are typically referred to as the koshas which are the physical, energetic, mental, subtle, and bliss sheaths. In our current understanding of yoga, we are working to unify these five bodies or layers of the human being. Another process of unification occurs between of the individual consciousness and the universal consciousness.
This unification is often referred to as Samadhi and is one of the primary transformations that occur within the practice of yoga. Observing this from a different angle, Samadhi is a transformation of perception in which disillusionments about the world are reformed so that the truth behind reality can be seen in its purest of form. Yoga, as a system, has developed into various branches through which people pursue the evolution and unification of the elements within their being. Each branch retains its own unique set of ideas and philosophies which defined the process and eventual obtainment of complete unification.
Article Source: http://EzineArticles.com/2597626