Yoga is not a belief system or a religion or even a philosophy; it is an extremely practical methodology for systematically expanding the conscious mind. Said another way, Yoga is the science for overcoming the self-destructive and limiting beliefs and internal programs that keep individual life bound to the experiences of the waking state of consciousness - the state in which life is alternately happy and sad, loving and hating, healthy and unhealthy, etc. There is no problem, mental, emotional, physical, societal, or environmental that can withstand the wholly beneficial power of the infinite mind...
Karma is action...and the consequence of that action -- the cause and the effect. It is neither good nor bad, it is simply action and consequence all happening simultaneously as every action generates some force of energy that returns to us in like kind.
Namaste, Namaskara or Namaskaram(Sanskrit), Hindustani pronunciation: [namast'e], from external sandi between namaḥ and te) is a common spoken greeting or salutation in South Asia. It is derived from Hinduism, and, in India and Nepal, it has multi-religious or else common usage where it may simply mean "I bow to you." In religious formulation, the meaning can be explained as:
"I bow to that inherent in you" (That refers to divinity, or "that which is divine".)
"I respect divinity within you that is also within me."
"The light within me honors the light within you." (in yoga)
The word is derived from Sanskrit namas, to bow, obeisance, reverential salutation, and te, "to you". Namaskar is considered a slightly more formal version than namaste, but both express deep respect. It is commonly used in India and Nepal by Hindus, Jains and Buddhists, and many continue to use this outside the Indian subcontinent. Namaste and Namaskar are used commonly in Northern India. However, Namaskara and Namaskaram are used in the southern part of India, instead of Namaste.
When spoken to another person, it is commonly accompanied by a slight bow made with hands pressed together, palms touching and fingers pointed upwards, in front of the chest. This gesture, called Añjali Mudrā, can also be performed wordlessly and carries the same meaning. In Indian and Nepali culture, the word is spoken at the beginning of written or verbal communication. However, upon departure, only the wordless hands-folded gesture is made.