Indonesian, an Austronesian language, is a standardized form of Malay and is spoken throughout Indonesia. About 23 million people speak Indonesian as their first language and a further 140 million speak it as a second language. Indonesia is a linguistically diverse region where the Indonesian language acts as a lingua franca, even though there are more native speakers of Javanese - about 75 million.
During the time Indonesia was a Dutch colony, the Latin alphabet was introduced to write Indonesian and a number of Dutch spellings were used. This alphabet was called ejaan lama (Old Script) in Indonesian.
In the 1930s, as part of the independence movement, the Indonesian language was standardised and the term Bahasa Indonesia was adopted as the name of the language.
source
wikipedia.org,
omniglot.com &
ethnologue.com