Advaita Vedanta is a philosophical and theological tradition within Hinduism that emphasizes the non-dual nature of reality.

The term "Advaita Vedanta" can be broken down into three parts:

1. Advaita: The word "Advaita" is a Sanskrit term that translates to "not two" or "non-dual." It denotes the belief that the ultimate reality is a singular, indivisible, and absolute entity. In Advaita Vedanta, this ultimate reality is referred to as Brahman.
2. Veda: The term "Veda" refers to the oldest scriptures of Hinduism, consisting of a large body of religious texts that include the Rigveda, Samaveda, Yajurveda, and Atharvaveda.
3. Anta: The word "anta" in Sanskrit means "end" or "conclusion." In this context, it refers to the culmination or essence of the teachings contained in the Vedas.

Advaita Vedanta, therefore, can be understood as the philosophical interpretation of the Vedas that emphasizes the non-dual nature of ultimate reality. This school of thought was established by the Indian philosopher Adi Shankaracharya (Adi Shankara) in the 8th century CE, who systematized the teachings of the Upanishads, Brahma Sutras, and Bhagavad Gita.

​The central teachings of Advaita Vedanta can be summarized as follows

1. Brahman is the Ultimate Reality: Advaita Vedanta teaches that the ultimate reality is Brahman, an infinite, unchanging, and undifferentiated absolute consciousness. Everything in existence emanates from and ultimately returns to Brahman.
2. Atman and Brahman are One: The individual self (Atman) is essentially the same as Brahman. The perceived separation between the self and the absolute reality is an illusion (Maya) created by the mind. Through self-inquiry and spiritual practice, one can transcend this illusion and realize the oneness of Atman and Brahman.
3. Moksha (Liberation): The ultimate goal of human life, according to Advaita Vedanta, is to achieve Moksha, or liberation, by realizing the non-dual nature of existence and experiencing the unity of Atman and Brahman. This realization leads to the dissolution of the cycle of birth and rebirth (Samsara) and the attainment of eternal bliss.

Advaita Vedanta is a profound philosophical tradition that has had a significant influence on Hindu thought and spirituality. It has also inspired various other philosophical and religious traditions, both within and outside India.

Hinduism is often referred to as "Sanatan Dharma" in many Indian languages. The term has a deep philosophical and cultural significance.

"Sanatan" is a Sanskrit word that means eternal, everlasting, or unchanging, and "Dharma" is a multi-faceted word with several meanings, including law, duty, morality, ethics, and religion. So, when combined, "Sanatan Dharma" can be understood as the "eternal religion" or the "eternal way of life."

Here are a few reasons why Hinduism is called Sanatan Dharma:

1. Ageless Tradition: Hinduism is considered one of the oldest religions in the world. Its roots can be traced back to the Indus Valley Civilization (around 2000-1500 BCE) and it has been evolving ever since. This long and uninterrupted tradition gives it an eternal quality.
2. Universal Principles: Sanatan Dharma is not just a religion but a way of life that espouses universal principles such as truth, non-violence, justice, compassion, and self-discipline. These principles are seen as eternal and unchanging, transcending time and culture.
3. Inclusive Philosophy: Hinduism has a very inclusive philosophy. It accommodates a wide range of beliefs, practices, and traditions within its fold. This inclusivity is seen as an eternal characteristic of the religion.
4. Endless Cycle of Creation and Destruction: In Hindu cosmology, the universe undergoes an endless cycle of creation, preservation, and destruction. This cyclical view of time gives the religion an eternal quality.
5. Continuity of Spiritual Knowledge: The Vedas, the oldest sacred texts of Hinduism, are believed to be a direct revelation of divine knowledge that has existed eternally. This eternal knowledge, passed down through generations, is central to the concept of Sanatan Dharma.

In summary, the term "Sanatan Dharma" reflects the timeless and eternal nature of Hinduism's principles and practices, and its ability to adapt and absorb different ideas while maintaining continuity with its ancient roots.