Sanatana Dharma is an ancient spiritual tradition of almost one billion years old. It constitutes of comprehensive spiritual, sacred and yogic science dealing with all aspects of life, culture, and religion. It is the great tradition behind teachings such as Ayurveda, Yoga, Vedic Astrology, Samkhya, Vedanta, and Tantra. These disciplines are rooted in Vedic lineages and transmissions going back to their very origins. It speaks of eternal laws which govern life and being in tune with it.
Sanatana Dharma provides its followers with an entire worldview, way of life and a rational view of reality. It is an ocean of ideas, values, practices, and beliefs which have adapted as time progressed. This spiritual path offers happiness, positive growth, fearlessness, a healthy sense of well-being, and wisdom. It is a value system which at its core is compacted with spiritual freedom, depth, and authenticity, through which one may achieve Moksha (मोक्ष - enlightenment, liberation).
Different texts give different lists of the duties, but in general Sanatana Dharma consists of virtues such as honesty, refraining from injuring living beings, purity, goodwill, mercy, patience, forbearance, self-restraint, generosity, and asceticism.
Sanatana Dharma by its very essence of sectarian and ideological thinking. The earliest glimpse of Sanatana Dharma can be found in the Rig Veda which saw nature as being part of the same cosmic equation which is ruled by the higher consciousness. The word Sanatana Dharma comes from the Sanskrit language, "Sanatana" which means Anadi (beginningless), does not cease to be and is eternal and everlasting. With its rich connotations, Dharma is not translatable to any other language. Dharma is from dhri, meaning to hold together, to sustain. Sanatana Dharma’s meaning is "Natural Law," or principles of reality which are inherent in the very nature and design of the universe. Thus the term Sanatana Dharma can be translated to mean "the natural, ancient and eternal way."
HINDUNISM AND SANATANA DHARMA
The word Sanatana Dharma means the original or the eternal dharma. Although this word is not new, it's used as an alternative of the word Hinduism is quite new. People who realized this fact that Hinduism is not a religion and that Hinduism itself doesn't have a name, came up with the idea of calling it Sanatana Dharma.
Quest of spirituality is something that we all at some point seek. It is universal in nature and therefore it doesn't need a name to separately identify itself. Vedic literature is heavily drenched with transcendental philosophy that invokes spirituality. So, it is neither a religion and nor does it have a particular name. Similarly, dharma is also universal because righteousness and humanity are also universal.
There are thousands of books starting from the ancient Vedas (Rig Veda, Yajur Veda, Saama Veda, Atharva Veda), Upanishads to Puranas, all try to portray the value system as it existed in those times.
Essentially if one is interested in understanding Sanatana Dharma it is essential to look at it as a value system rather than a religion. It is a living, breathing aspect of our culture which has undergone tremendous changes as any culture should.