Preferential voting is required in Australia. It’s largely unique to our political scene, reflecting the number and diversity of smaller parties that participate in elections. It is a system of voting that allows a citizen to individually number and rank all candidates for both houses of parliament according to their preferences. It is employed when no one candidate or party wins outright, based on first preference votes. It means a citizen’s vote can still be counted, even if their first choice of candidate is eliminated due to a lack of votes. On a ballot paper, placing a number one against a candidate is considered the first preference or primary vote. If no candidate secures an absolute majority of primary votes, the candidate with the fewest votes is then eliminated from the count.
The votes for this eliminated candidate are then redistributed among the remaining candidates according to the number two preference indicated on the original ballot. This process of elimination based on preferences continues until a candidate secures an absolute majority.
Such a process enables a two-party system to ultimately emerge, whereby all votes are effectively divided between two major parties – in this case, the Labor and Liberal parties.
Full Article: What is preferential voting | Preferential voting | SBS World News.