The Australian system of governance is split into 3 parts, The Executive which includes the head of state and the cabinet, the Legislature which includes the Senate and the House of Representatives, and the Judiciary, which encompasses the courts, and acts as the judicial arm of governance. The practice of dividing government into three arms is known as the 'separation of powers' or 'trias politica'. This was done in order to increase the checks and balances in government, as each of the arms would have little influence over the other. This is especially important in the case of the judiciary, which must not be seen as dispensing the justice of a particular party. .
The many political parties within Australia are what form the functions of the legislative arm of government. The legislature oversees the activities of the other two arms of government, with the purpose of changing and amending laws when it deems necessary, or rather, when the party in power deems necessary, depending on whether or not they have a clear majority in the 150 seat strong House of Representatives. Within the legislature is also the Senate, which is comprised of 76 seats, and acts as the reviewing body for proposed policy, and also acts as a voice for the smaller states, as each state has 12 senators, and each territory has 2, regardless of the population size. While political parties have a large degree of influence in the House of Representatives (also known as the lower house), they may not necessarily have the same influence in the Senate (also known as the upper house). The party composition of the senate is usually categorised into three scenarios: a friendly Senate, which means that the party which holds a majority in the Lower House, also holds a majority in the Upper House, a hostile Senate, in which the elected party does not have a majority in the Senate and as such is blocked heavily on its proposed legislation, and a neutral Senate, in which no party holds a clear majority in the Senate, and a greater degree of inter-party discourse must take place for legislation to be passed.