Bengali also known by its endonym Bangla (বাংলা Bengali pronunciation: [ˈbaŋla]), is an Indo-Aryan language and is the lingua franca of the Bengal region of the Indian subcontinent. It is the most widely spoken language of Bangladesh and the second most widely spoken of the 22 scheduled languages of India, after Hindi. With approximately 228 million native speakers and another 37 million as second language speakers, Bengali is the seventh most-spoken native language and the sixth most spoken language by total number of speakers in the world.
Bengali is the official and national language of Bangladesh, with 98% of Bangladeshis using Bengali as their first language. Within India, Bengali is the official language of the states of West Bengal, Tripura and the Barak Valley region of the state of Assam. It is the most widely spoken language in the Andaman and Nicobar Islands as well in the Bay of Bengal, and is spoken by significant populations in other states including Arunachal Pradesh, Delhi, Chhattisgarh, Jharkhand, Meghalaya, Mizoram, Nagaland and Uttarakhand. Bengali is also spoken by the significant global Bengali diaspora (Bangladeshi diaspora and Indian Bengalis) communities in Pakistan, the United Kingdom, the United States, and the Middle East.
Source : Wikipedia