The internal territories are the Australian Capital Territory, Jervis Bay Territory and the Northern Territory of Australia. The inhabited external territories are Norfolk Island, Christmas Island and the Cocos and Keeling Islands. The uninhabited external territories are the Coral Sea Islands Territory[?], Heard and McDonald Islands and the Australian Antarctic Territory.
The states originated as separate British colonies prior to Federation (in 1901). Their powers are protected by the Australian constitution, and Commonwealth legislation only applies to the states where permitted by the constitution. The territories, by contrast, are from a constitutional perspective directly subject to the Commonwealth government. The Australian Parliament has powers to legislate in the territories that it does not possess in the states.
Most of the territories are directly administered by the Commonwealth government, while three (the Northern Territory, the Australian Capital Territory and Norfolk Island) administer themselves. In the self-governing territories the Australian Parliament retains the full power to legislate, and can override laws made by the territorial institutions, which it has done on rare occasion. For the purposes of Australian (and joint Australia-New Zealand) intergovernmental bodies, the Northern Territory and the Australian Capital Territory are treated as a state.
Furthermore, the distribution of powers between the Commonwealth and the territories is different from that between the Commonwealth and the states. In the Northern Territory, the Commonwealth retains the power to directly administer uranium mining and Aboriginal lands, powers which it does not possess with respect to the states.
The head of each state is the Governor, who is appointed by the Queen, which by convention she does on the advice of the state Premier. The heads of the Northern Territory and of Norfolk Islands are called Administrators, who by contrast are appointed by the Governor-General. The Australian Capital Territory has neither an Administrator or Governor, and is unique in Australia in that its chief executive (the Chief Minister) is also head of government, and is elected by the Legislative Assembly. A few of the powers exercised in other states or territories by the Governor or Administer are exercised in the Australian Capital Territory by the Governor-General, such as the power to dissolve the Legislative Assembly.
Each state has a Parliament. Every state except Queensland has a bicameral Parliament, with a lower house (generally called the Legislative Assembly) and an upper house (generally called the Legislative Council). Queensland abolished its Legislative Council in the 1920s. The three self-governing territories, the ACT, the Northern Territory and Norfolk Island, have unicameral Legislative Assemblies.
The head of government of each state is called the Premier. The Premier is appointed by the state Governor. In normal circumstances the Governor will appoint as Premier whoever leads the party or coalition which exercises control of the lower house (in the case of Queensland, the only house) of the state Parliament. However, in times of constitutional crisis, the Governor can appoint someone else as Premier. The head of government of a self-governing territory is called the Chief Minister, and likewise they are appointed by the territory's Administrator, in normal circumstances to whoever controls the territory's Legislative Assembly.