The mountains in the nation's east give way to a flat coastal plain; western Brunei consists of hilly lowlands. The tropical climate is typically hot and humid with frequent rain. About two thirds of the population are Malays, but the Chinese community, consisting of about 15% of the people, dominates the economy. Some 6% of the people are of indigenous descent. Malay is the official language, but English and Chinese are also spoken. Islam is the predominant and official religion; there are minorities of Buddhists, Christians, and those holding traditional beliefs.