Hindustani, commonly known as Hindi-Urdu and historically as Hindavi, Urdu, and Rekhta, is the lingua franca of North India and Pakistan. It is an Indo-Aryan language, deriving primarily from the Khariboli dialect of Delhi, and incorporates a large amount of vocabulary from Persian, Arabic, Sanskrit and Turkic. It is a pluricentric language, with two official forms, Standard Hindi and Standard Urdu, which are standardized registers of it. The colloquial languages are all but indistinguishable, and even though the official standards are nearly identical in grammar, they differ in literary conventions and in academic and technical vocabulary, with Urdu retaining stronger Persian, Central Asian and Arabic influences, and Hindi relying more heavily on Sanskrit. Before the Partition of India, the terms Hindustani, Urdu, and Hindi were synonymous; all covered what would be called Urdu and Hindi today. The term Hindustani is still used for the colloquial language and lingua franca of North India and Pakistan, for example for the language of Bollywood films, as well as for several quite different varieties of Hindi spoken outside the Subcontinent, such as Fiji Hindi and the Caribbean Hindustani of Suriname and Trinidad. Wikipedia