Hinduism is the predominant and indigenous religious tradition of South Asia. Hinduism is often referred to as Sanātana Dharma (a Sanskrit phrase meaning "the eternal law") by its adherents. Generic "types" of Hinduism that attempt to accommodate a variety of complex views span folk and Vedic Hinduism to bhakti tradition, as in Vaishnavism. Hinduism also includes yogic traditions and a wide spectrum of "daily morality" based on the notion of karma and societal norms such as Hindu marriage customs.

Hinduism is formed of diverse traditions and has no single founder.[3] Among its roots is the historical Vedic religion of Iron Age India, and as such Hinduism is often called the "oldest living religion" or the "oldest living major tradition".

Demographically, Hinduism is the world's third largest religion, after Christianity and Islam, with approximately one billion adherents, of whom approximately 828 million live in the Republic of India. Other significant populations are found in Nepal (23 million), Bangladesh (14 million) and the Indonesian island of Bali (3.3 million).

A large body of texts is classified as Hindu, divided into Śruti ("revealed") and Smriti ("remembered") texts. These texts discuss theology, philosophy and mythology, and provide information on the practice of dharma (religious living). Among these texts, the Vedas are the foremost in authority, importance and antiquity. Other major scriptures include the Upanishads, Purāṇas and the epics Mahābhārata and Rāmāyaṇa. The Bhagavad Gītā, a treatise from the Mahābhārata, spoken by Krishna, is of special importance.