Indonesian (Bahasa Indonesia) is the official language of Indonesia. The Indonesian name for the language is Bahasa Indonesia (literally "the language of Indonesia"). This term can sometimes still be found in written or spoken English. In addition, the language is sometimes referred to as "Bahasa" by English speakers, though this simply means "language" and thus does not technically specify the Indonesian language.
Indonesian (in its most standard form) is largely mutually intelligible with the official Malaysian form of Malay. However, it does differ from Malaysian in several aspects, with differences in pronunciation and vocabulary. These differences are mainly due to the Dutch and Javanese influences on Indonesian.
The language is spoken throughout Indonesia (and East Timor), although it is used most extensively as a first language in urban areas and usually as a second or third language in more rural parts of Indonesia. It is also spoken by an additional 1.5+ million people worldwide.
Indonesian as a modern dialect of Malay has borrowed heavily from many languages, including: Sanskrit, Arabic, Persian, Portuguese, Dutch, Chinese and many other languages, including other Austronesian languages. It is estimated that there are some 750 Sanskrit loan words in modern Indonesian, 1,000 Arabic loans, some of Persian and Hebrew origin, some 125 words of Portuguese (also Spanish and Italian) origin and a staggering number of some 10,000 loan words from Dutch. The latter also comprises many words from other European languages, which came via Dutch, the so-called "International Vocabulary". The vast majority of Indonesian words, however, come from the root lexical stock of its Austronesian (incl. Old Malay) heritage.