Java is an island belongs to Indonesian Republic. With a population over 135 million is the world's most populous island, and one of the most densely-populated places on the globe, is the home of 60 percent of the Indonesian population. The Indonesian capital city is Jakarta located on the western Java. Formed mostly as the result of volcanic eruptions, Java is the 13th largest island in the world and the fifth largest island in Indonesia. A chain of volcanic mountains forms an east-west spine along the island. It has three main languages, though Javanese is dominant and it is the native language of about 60 million people in Indonesia, most of whom live on Java. Most of its residents are bilingual, with Indonesian as their first or second languages.