A system of government in which executive is formed from, and responsible to, a parliament, and a head of government (for example, the Prime Minister) is different from a head of state (for example, the Queen).

A system of voting to rank candidates in order of preference. It is necessary for a winning candidate to achieve an absolute majority (50 per cent plus one). If no candidate achieves an absolute majority, a candidate with the fewest number of first preferences is excluded from the count, and his or her votes are distributed among the remaining candidates according to second preferences. This process is continued until one candidate achieves an absolute majority. It is the dominant form of voting in Australian politics (as compared with simple majority systems of voting).

A representation of parties, groups or individuals in a legislature in proportion to a number of votes they receive in an election. In Australia, proportional representation describes the way candidates are elected in multi-member electorates such as the Senate.