Hinduism is one of the world's oldest religions originating in India with no single founder. It is a diverse set of beliefs and traditions with approximately 1 billion adherents worldwide, most living in India. Core Hindu beliefs include reincarnation, dharma, karma, and samsara. Hindus worship many gods like Brahma, Vishnu, Shiva and their avatars while believing in an overarching divine power called Brahman. Caste, the varna system, and concepts like moksha also play important roles in Hindu philosophy and way of life.