Hinduism is an Indian Dharma, or a way of life, widely practiced in South Asia. Hinduism has been called the oldest religion in the world, and some practitioners and scholars refer to it as Sanātana Dharma, "the eternal tradition," or the "eternal way," beyond human history. Scholars regard Hinduism as a fusion or synthesis of various Indian cultures and traditions, with diverse roots and no founder. This "Hindu synthesis" started to develop between 500 BCE and 300 CE, following the Vedic period (1500 BCE to 500 BCE).
Although Hinduism contains a broad range of philosophies, it is linked by shared concepts, recognisable rituals, cosmology, shared textual resources, and pilgrimage to sacred sites. Hindu texts are classified into Śruti ("heard") and Smṛti ("remembered"). These texts discuss theology, philosophy, mythology, Vedic yajna, Yoga, agamic rituals, and temple building, among other topics. Major scriptures include the Vedas and Upanishads, the Bhagavad Gita, and the Agamas. Sources of authority and eternal truths in its texts play an important role, but there is also a strong Hindu tradition of the questioning of this authority, to deepen the understanding of these truths and to further develop the tradition.