Hinduism (known as Hindū Dharma in modern Indian languages) is a religious tradition that originated in the Indian subcontinent. In contemporary usage Hinduism is also sometimes referred to as Sanātana Dharma (सनातन धर्म), a Sanskrit phrase meaning "eternal law".
With its origins in the Vedic civilization it has no known founder, being itself a conglomerate of diverse beliefs and traditions. It is the world's oldest existent religion, and has approximately a billion adherents, of whom about 905 million live in India and Nepal. This places it as the world's third largest religion after Christianity and Islam. Other countries with large Hindu populations include Bangladesh, Sri Lanka, Pakistan, Indonesia, Malaysia, Singapore, Mauritius, Fiji, Suriname, Guyana and Trinidad and Tobago.
Hinduism contains a vast body of scriptures. Divided as revealed and remembered and developed over millennia, these scriptures expound on theology, philosophy and mythology, providing spiritual insights and guidance on the practice of dharma (religious living). Among such texts, the Vedas and the Upanishads are the foremost in authority, importance and antiquity. Other major scriptures include the Tantras, the sectarian Agamas, the Purāṇas and the epics Mahābhārata and Rāmāyaṇa. The Bhagavad Gītā, a treatise excerpted from the Mahābhārata, is sometimes called a summary of the spiritual teachings of the Vedas.