The Republic of Indonesia is located in the Malay Archipelago, the world's largest archipelago, between Indochina and Australia, between the Indian and Pacific Oceans. It is the most populous Muslim-majority nation in the world and the fourth most populous overall. It has had free elections since the 1998 Revolution which led to the resignation of President Suharto, who came to power in 1965.

Indonesia's 18,108 islands, of which about 6,000 are inhabited, are scattered around the equator, giving the country a tropical climate. The largest populated islands are Java, one of the most densely populated regions on Earth, where about half of the population lives, Sumatra, Borneo (shared with Malaysia and Brunei), New Guinea (shared with Papua New Guinea) and Sulawesi. The country borders Malaysia on the island of Borneo (Indonesian: Kalimantan), Papua New Guinea on the island of New Guinea and East Timor on the island of Timor. In addition to the capital city of Jakarta, principal Indonesian cities of high population include Surabaya, Bandung, Medan, Palembang, and Semarang.

Its location on the edges of tectonic plates, specifically the Pacific, Eurasian, and Australian, means Indonesia is frequently hit by earthquakes and the resulting tsunamis. Indonesia is also rich in volcanoes, the most famous being the now vanished Krakatau ( Krakatoa ), which was located between Sumatra and Java. Most Indonesians speak a local language ( bahasa daerah ) as their first tongue, but the official national language, Indonesian (locally called Bahasa Indonesia or simply Bahasa , meaning language ) is almost universally taught in schools and is spoken by nearly every Indonesian.

Some art forms in Indonesia have been influenced by several cultures. The famous Javanese and Balinese dances, for example, contain aspects of Hindu culture and mythology. But as a matter of fact, the diversity of Indonesian culture has come as a result of a long process of acculturation between the original customs and myriad of influences. Also well-known are the Javanese and Balinese wayang kulit Shadow puppet theatre shows, displaying several mythological events. Several Islands are famous for their batik and ikat cloth.