India is a historic country with three main names.

India

The first Article of the Constitution of India, which deals with the official name, states that "India, that is Bharat, shall be a union of states." Thus, not only in usage but officially India and Bharat are both accorded primary status. The name India is derived from the river Indus.

The original name of the river came from the fact that in the north-west of the subcontinent, there are seven main tributaries of the one river. The local inhabitants therefore called it Sapta-Sindhu, meaning the land of seven rivers. As the seven tributaries are part of the one river, the entire river system came to be known in time as Sindhu.

Persian explorers visited the area even in ancient times, and their practise when converting Sanskrit words was to aspirate the 'S'. Thus Sindhu became Hindu.

The Greeks, dropping the 'H', derived Indos. The Latin form of Indos is Indus, the name by which the river system is still known in the West. Its name was given to the entire subcontinent by the Romans, who adapted it to the current India.

The word India is the form used by Europeans over the ages.

Interestingly the Vedas did not assign any particular name for India, although some scholars assert that references to Indu in the Rig Veda relate to India's present name. Many traditional literary/cultural works from around the globe lack definite terminology for their home culture as a political unit; China, Greece, and many other civilizations lacked fixed names for themelves in traditional literature during many early periods.

Bharat

The name "Bharat" is derived from either of two ancient Hindu kings named Bharata, though it is more commonly accepted that the name derives from that of the son of Dushyanta , whom the Mahabharata credits with bringing the whole of Bharatvarsha under his rule and securing the title of an emperor. "Bha" in Sanskrit means knowledge or light, and "rat" is a verb for 'doing'. Bharat is therefore 'the one who is in search of knowledge.' Both names are commonly in use.

Hindustan

Hindustan is another name which has been used from the time of its introduction in Mughal times onwards referring to the 'land of the Hindus' (Hindu meaning one of Indus/Sindhu origin, i.e. Indian, 'stan' land). The association of Hindu with practitioners of the Vedic stream of religion now known as Hinduism only truly took root from around the 15th and 16th centuries (as evidenced in works by people like Kabir). In the time of the British Raj, the term Hindustan was popularly used to describe not only India in general but North Indian culture and the mix language of Urdu and Hindi (by which name the melded vernacular is still known today). Thus, while Hindustan is still used by some as a signifier of the nation of India, this usage is debated, though Jai Hind (Victory to India) is still popular throughout. In any case, there are geographical, political and regional preferences in the use of the various terminologies.