Hindustani (Hindustani: हिन्दुस्तानी, ہندوستانی [ˌɦɪnd̪ʊsˈt̪aːniː], lit. '"of Hindustan"'), historically also known as Hindavi, Dehlvi 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 Sanskrit, Persian, Arabic and Chagatai. It is a pluricentric language, with two official forms, Modern Standard Hindi and Modern Standard Urdu, which are its standardised registers, and which may be called Hindustani or Hindi-Urdu when taken together. The colloquial registers are mostly 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