Hindu refers to an identity associated with the philosophical, religious and cultural systems that are indigenous to the Indian subcontinent. In common use today, it refers to an adherent of Hinduism. However, in the Constitution of India, the word "Hindu" has been used in places to denote persons professing any religion originated in India (i.e. Hinduism, Jainism, Buddhism orSikhism).
The word Hindu is derived (through Persian) from the Sanskrit word Sindhu, the historic local name for the Indus River in the northwestern part of the Indian subcontinent (modern day Pakistan and Northern India)
With more than a billion adherents, Hinduism is the world's third largest religion. The vast majority of Hindus, approximately 940 million, live in India. Other countries with large Hindu populations include Nepal,Bangladesh, Sri Lanka, Mauritius, Suriname, Guyana, Trinidad & Tobago, United States, Fiji, United Kingdom, Singapore, Canada and the island of Bali in Indonesia