Java (lang-idJawa) is an island of Indonesia and the site of its capital (Capital (political)) city, Jakarta. Once the center of powerful Hindu-Buddhist kingdoms, Islamic sultanates (The spread of Islam in Indonesia), and the core of the colonial Dutch East Indies, Java now plays a dominant role in the economic and political life of Indonesia. Home to a population of 130 million in 2006, it is the most populous island (List of islands by population) in the world, ahead of Honsh?, the main island of Japan. Java is also one of the most densely populated (Population density) regions on Earth.

Formed mostly as the result of volcanic events, Java is the 13th largest island (List of islands by area) 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 is the native language of 60 million people in Indonesia, most of whom live on Java. Most residents are bilingual (Multilingualism), with Indonesian (Indonesian language) as their first or second language. While the majority of the people of Java are Muslim, Java has a diverse mixture of religious beliefs, ethnicities and cultures.