Grenada is an island country in the Caribbean located between the Caribbean Sea and the Atlantic Ocean, north of Trinidad and Tobago. Grenada is volcanic in origin with central mountains. The government system is a parliamentary democracy and a Commonwealth realm; the chief of state is the queen of the United Kingdom, and the head of government is the prime minister. Grenada has a mixed economic system which includes a variety of private freedom, combined with centralized economic planning and government regulation. Grenada is a member of the Caribbean Community (CARICOM) and the Organization of Eastern Caribbean States (OECS).