Kauravi (Hindi: कौरवी, Urdu: کَوروی), also known as Khaṛībolī, is a dialect of Hindustani descended from Shauraseni Prakrit that is mainly spoken by local people in Western Uttar Pradesh, across Yamuna river (Jamna Paar) in Delhi, in Haryana, border areas of Haryana and Uttar Pradesh, and in whole of Uttarakhand plains.
Modern Hindi and Urdu are two standard registers of Hindustani, descending from Old Hindi, originally called Hindavi and Delhavi which gained prestige when it was accepted along with Persian as a language of the courts. Before that, it was only a language the Persianate states (like Delhi Sultanate) spoke to their subjects in, and later as a sociolect of the same ruling classes.