A central government is the government that is a controlling power over a unitary state. Another distinct but sovereign political entity is a federal government, which may have distinct powers at various levels of government, authorized or delegated to it by the Federation and mutually agreed upon by each of the federated states. Though inappropriate, the adjective "central" is also sometimes used to describe the government of a federation, such as in India. The structure of central governments varies. Many countries have created autonomous regions by delegating powers from the central government to governments on a sub-national level, such as regional, state, provincial, local and other instances. Based on a broad definition of a basic political system, there are two or more levels of government that exist within an established territory and government through common institutions with overlapping or shared powers as prescribed by a constitution or other law. Common responsibilities of this level of government which are not granted to lower levels are maintaining national security and exercising international diplomacy, including the right to sign binding treaties. Essentially, the central government has the power to make laws for the whole country, in contrast with local governments. The difference between a central government and a federal government is that the autonomous status of self-governing regions exists by the sufferance of the central government and are often created through a process of devolution. As such they may be unilaterally revoked with a simple change in the law. An example of this was done in 1973 when the Northern Ireland Constitution Act 1973 abolished the government of Northern Ireland which had been created under the Government of Ireland Act 1920. It is common for a federal government to be brought into being by agreement between a number of formally independent states and therefore its powers to affect the status of the balance of powers is significantly smaller (as in the United States). Thus federal governments are often established voluntarily from 'below' whereas devolution grants self-government from above. Examples Unitary states There are, and have been, many countries which have delegated powers, some include: People's Republic of China – see autonomous administrative divisions of China Denmark – see the autonomous regions of the Faroe Islands and Greenland France Republic of China Georgia – see autonomous republics Japan Republic of Korea Indonesia Spain – see autonomous communities Philippines - see Provinces of the Philippines