Hinduism is the predominant and indigenous religious tradition of South Asia. Hinduism is often referred to as '''' (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. 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 more than a billion adherents, of whom approximately 1 billion, live in India. Other significant populations are found in Nepal (23 million), Bangladesh (14 million) and the Indonesian island of Bali (3.3 million).