Peope from the Indian Subcontinent and its diaspora around the world.
Countries with Desis include: India, Pakistan,Bangladesh, Sri Lanka, Bhutan, USA, European continent, Suriname, Guyana, Trinidad, Fiji, Uganda, Canada, Parts of Afganistan, Brazil, U.A.E and many more.
Desi is the newest term for South Asians, the name for South Asians before British Raj was Hindustani, Hindustani was used since the ancient times started by the Persians.
Boy - Hey you look South Asian you must be Desi!
Girl - Yeah