There are many different voting and counting systems. This site provides information about these systems in government elections.
Preferential voting – where a voter indicates an order of preference for the candidates on the ballot paper.
Proportional representation – where a candidate is elected if they receive a set proportion of the vote.
First past the post – only used for referendums and polls, in NSW – votes are counted and the most votes wins, even if that number is less than 50% of the formal vote.