Yamas or Control Factors - the first part of the Ashtanga Yoga System, are the ways of perceiving and reacting which are to be refrained from, for the reason that indulgence in these proscribed actions and thoughts will lead to scattering and diluting of the power of consciousness. A diluted and scattered consciousness is incapable of perceiving rationally, and behaving skilfully, and therefore is likely to bring misfortunes upon its own head, through misguided actions and thoughts.
Niyamas are the prescribed ways of being are thoughts and actions, the second part of the Ashtanga Yoga System, which being regularly activated, lead to the support state of consciousness necessary for attaining one-pointed concentration, and full-spread awareness powers. Without these powers of higher concentration and higher awareness, progress on the yogic path of self-willed evolution is impossible.
These Yamas and Niyamas form the 1st and 2nd part of the 8-Part Ashtanga Yoga System. Each of these Yamas and Niyamas have been detailed in this module, which is a sub-section of the Chapter 2 of Patanjali's Yoga Sutra - Sadhana Pada.
Yoga Aspirants would surely enjoy this unique perspective on the Yamas & Niyamas, however, in order to fully appreciate the depth and perceptive insight of Maharashi Patanjali on the Psyche, we would recommend aspiring students to enroll for the other sub-modules that make up entire Raja Yoga teachings.