Australia, officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the world's smallest continent and a number of islands in the Southern, Indian, and Pacific Oceans. Neighbouring countries include Indonesia, East Timor and Papua New Guinea to the north, the Solomon Islands, Vanuatu and the French dependency of New Caledonia to the northeast, and New Zealand to the southeast.
The mainland of the continent of Australia has been inhabited for more than 42,000 years by Indigenous Australians. After sporadic visits by fishermen from the north and by European explorers and merchants starting in the seventeenth century, the eastern half of the mainland was claimed by the British in 1770 and officially settled through penal transportation as the colony of New South Wales on 26 January 1788. As the population grew and new areas were explored, another five largely self-governing Crown Colonies were successively established over the course of the 19th century.
On 1 January 1901, the six colonies became a Federation, and the Commonwealth of Australia was formed. Since federation, Australia has maintained a stable liberal democratic political system and remains a Commonwealth Realm. The capital city is Canberra, located in the Australian Capital Territory. The current national population is around 20.6 million people, and is concentrated mainly in the large coastal cities of Sydney, Melbourne, Brisbane, Perth, and Adelaide.
Australia consists of six states, two major mainland territories, and other minor territories. The states are New South Wales, Queensland, South Australia, Tasmania, Victoria and Western Australia. The two major mainland territories are the Northern Territory and the Australian Capital Territory. In most respects, the territories function similarly to the states, but the Commonwealth Parliament can override any legislation of their parliaments. By contrast, federal legislation overrides state legislation only with respect to certain areas as set out in Section 51 of the Constitution; all residual legislative powers are retained by the state parliaments, including powers over hospitals, education, police, the judiciary, roads, public transport and local government. Each state and territory has its own legislature (unicameral in the case of the Northern Territory, the ACT and Queensland, and bicameral in the remaining states). The lower house is known as the Legislative Assembly (House of Assembly in South Australia and Tasmania) and the upper house is known as the Legislative Council. The heads of the governments in each state and territory are called premiers and chief ministers, respectively. The Queen is represented in each state by a governor; an administrator in the Northern Territory, and the Governor-General in the ACT, have analogous roles.
Australia also has several minor territories; the federal government administers a separate area within New South Wales, the Jervis Bay Territory, as a naval base and sea port for the national capital. In addition Australia has the following, inhabited, external territories: Norfolk Island, Christmas Island, Cocos (Keeling) Islands, and several largely uninhabited external territories: Ashmore and Cartier Islands, Coral Sea Islands, Heard Island and McDonald Islands and the Australian Antarctic Territory.
