Hindu refers to an identity associated with the philosophical, religious and cultural systems that are indigenous to the Indian subcontinent. As used in the Constitution of India, the word "Hindu" is also attributed to all persons professing any Indian religion (i.e. Hinduism, Jainism, Buddhism or Sikhism). In common use today, it refers to an adherent of Hinduism.
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, Fiji and the island of Bali.
Hinduism, its religious doctrines, traditions and observances are very typical and inextricably linked to the culture and demographics of India. Hinduism has one of the most ethnically diverse bodies of adherents in the world. It is hard to classify Hinduism as a religion because the framework, symbols, leaders and books of reference that make up a typical religion are not uniquely identified in the case of Hinduism. Hinduism is almost 4,000 years old. Most commonly it can be seen as a "way of life" which gives rise to many other forms of religions.
Large tribes and communities indigenous to India are closely linked to the synthesis and formation of Hindu civilization. People of East Asian roots living in the states of north eastern India and Nepal were also a part of the earliest Hindu civilization. Immigration and settlement of people from Central Asia and people of Indo-Greek heritage have brought their own influence on Hindu society.
Diwali celebrations in Little India, Singapore.
The roots of Hinduism in southern India, and among tribal and indigenous communities is just as ancient and fundamentally contributive to the foundations of the religious and philosophical system.
Ancient Hindu kingdoms arose and spread the religion and traditions across Southeast Asia, particularly Thailand, Nepal, Burma, Malaysia, Indonesia, Cambodia, Laos, Philippines, and what is now central Vietnam. A form of Hinduism particularly different from Indian roots and traditions is practiced in Bali, Indonesia, where Hindus form 90% of the population. Indian migrants have taken Hinduism and Hindu culture to South Africa, Fiji, Mauritius and other countries in and around the Indian Ocean, and in the nations of the West Indies and the Caribbean.
Source: Wikipedia, "Hindu", available under the CC-BY-SA License.