Urdu historically spelled Ordu, is an Indo-Aryan language of the Indo-Iranian branch, belonging to Indo-European family of languages. It developed under Persian and Arabic, to some lesser degree also under Turkic influence in South Asia during the Delhi Sultanate and Mughal Empire.Urdu refers to a standardised register of Hindustani termed khadiboli, that emerged as a standard dialect. In general, the term "Urdu" can encompass dialects of Hindustani other than the standardised versions. Standard Urdu has approximately the twentieth largest population of native speakers, among all languages. It is the national language of Pakistan as well as one of the 21 official languages of India. There are 60,503,579 people speaking Urdu language on World total basis.

Urdu is often contrasted with Hindi, another standardised form of Hindustani. The main difference between the Hindi and Urdu is that Standard Urdu is written in Nastaliq calligraphy style of the Perso-Arabic script and some words are taken from Persian and Arabic, while Standard Hindi is written in Devanagari and has inherited significant vocabulary from Sanskrit. Linguists therefore consider Urdu and Hindi to be two standardized forms of the same language. According to the 1999 data, Hindi/Urdu is the fifth most spoken language in the world. According to Comerie (1998 data), Hindi-Urdu is the second most spoken language in the world, with 330 million native speakers, after Mandarin and possibly English.

Because of Urdu`s similarity to Hindi, speakers of the two languages can usually understand one another, if both sides refrain from using specialized vocabulary. Indeed, linguists sometimes count them as being part of the same Genetic languag. However, Urdu and Hindi are socio-politically different, and people who self-describe as being speakers of Hindi would question their being counted as native speakers of Urdu, and vice-versa.

In India, Urdu is spoken in places where there are large Muslim majorities or cities which were bases for Muslim Empires in the past. These include parts of Uttar Pradesh (namely Lucknow), Delhi, Bhopal, Hyderabad, Bangalore, and Mysore. Some Indian schools teach Urdu as a first language and have their own syllabus and exams. Indian madrasahs also teach Arabic as well as Urdu. India has more than 2,900 daily Urdu newspapers. Outside South Asia, it is spoken by large numbers of migrant South Asian workers in the major urban centers of the Persian Gulf countries and Saudi Arabia. Urdu is also spoken by large numbers of immigrants and their children in the major urban centers of the United Kingdom, the United States, Canada, Norway and Australia.

Official status
Urdu is the national language of Pakistan and is spoken and understood throughout the country. It shares official language status with English. It is used in education, literature, office and court business, media, and in religious institutions. It holds in itself a depository of cultural, religious and social heritage of the country. Although English is used in most elite circles, and Punjabi has a plurality of native speakers, Urdu is the lingua franca (lingua franca is any language widely used beyond the population of its native speakers) and is expected to prevail. Urdu is also one of the officially recognized state languages in India and has official language status in the Indian states of Andhra Pradesh, Bihar, Jammu and Kashmir, and Uttar Pradesh, and the national capital, Delhi. While the government school system in most other states emphasizes Standard Hindi, at universities in cities such as Lucknow, Aligarh and Hyderabad, Urdu is spoken, learned, and regarded as a language of prestige.

Classification and related languages
Urdu can be considered to be a part of a dialect continuation which extends across eastern Iran, Afghanistan and modern Pakistan right into north India. These dialects have similar grammatical structures and share a large portion of their vocabulary. Punjabi, for instance, is very similar to Urdu Punjabi written in the Shahmukhi script can be understood by speakers of Urdu with little difficulty, but spoken Punjabi has a very different pronunciation and can be harder to understand for Urdu speakers.

Dialects
Urdu has four recognised dialects Dakhini, Pinjari, Rekhta, and Modern Vernacular Urdu (based on the Khariboli dialect of the Delhi region). Sociolinguists also consider Urdu as one of the four major variants of the Hindi Urdu dialect continuation. Modern Vernacular Urdu is the form of the language that is least widespread and is spoken around Delhi, Lucknow, Karachi and Lahore, it becomes increasingly different from the original form of Urdu as it loses some of the complicated Persian and Arabic vocabulary used in everyday terms.Dakhini is spoken in Maharashtra state in India and around Hyderabad. It has fewer Persian and Arabic words than standard Urdu. In addition, Rekhta the language of Urdu poetry, is sometimes counted as a separate dialect.