Indonesian (bahasa Indonesia [baˈha.sa in.doˈne.sja]) is the official language of Indonesia. It is a group of varieties of Malay, an Austronesian language that has been used as a lingua franca in the multilingual Indonesian archipelago for centuries. Indonesia is the fourth most populous nation in the world. Of its large population, the majority speak Indonesian, making it one of the most widely spoken languages in the world.
Most Indonesians, aside from speaking the national language, are fluent in at least one of the more than 700 indigenous local languages; examples include Javanese, Sundanese and Balinese, which are commonly used at home and within the local community. However, most formal education, and nearly all national mass media, governance, administration, judiciary, and other forms of communication, are conducted in Indonesian. The term “Indonesian” is particularly associated with the national standard dialect, which is confined to formal situations, existing in a diglossic relationship with vernacular Malay idioms, which are used as instruments of daily communication.