Australia has a system known as preferential voting for its elections.
Under this system, voters can number and rank all candidates for both houses of parliament from most preferred to least preferred.
The system is used when no one candidate secures an absolute majority of the primary votes.
House of Representatives
On federal election day, voters will be given two ballot papers - one for the House of Representatives and one for the Senate.
On the green House of Representatives ballot paper, voters will need to put the number 1 next to their first choice candidate and then number every other box.
The counting of first preference votes takes place initially and if no one candidate secures an absolute majority, the candidate with the least number of votes is eliminated from the count.
MP Bob Katter with ballot papers in 2016. Source: AAP
The votes for the eliminated candidate are then redistributed among the remaining candidates starting with the number two preference from the original ballot.
This process of elimination based on the preferences continues until one candidate secures an absolute majority.
Evan Ekin-Smyth from the Australian Electoral Commission told SBS News, "your first preference, your candidate there might get excluded. If they are, then we move on to your second preference. If that candidate is then excluded, your ballot keeps on travelling from preference to preference until it ends up in a pile and counted".
"So ultimately, you preferencing number seven ahead of number eight means that you might get that candidate ahead of your least favourite candidate which is important, your vote always counts."
Mr Ekin-Smyth said that's why it's "vital" to number every box on the green ballot paper.
Pauline Hanson with a 2016 senate ballot paper. Source: AAP
"Preferential voting essentially means that your vote can go further. If your preferred candidate, your number one candidate, doesn't end up being one of the top two candidates, in many systems your vote would then be set aside," he said.
"In the Australian system it's not, so carefully number every box on the House of Representatives ballot paper, the green ballot paper, because your vote will be counted."
Dr Peter Chen from the University of Sydney said preferential voting allows for a greater number and diversity of candidates.
"In the Australian system using the numbering preference system it can mean that a less popular candidate can be eliminated and the general preferences that the elector has can be redistributed until one candidate receives 50 per cent plus one for the lower house of the votes," he said.
"And Australia really introduced that with an attempt to, in a sense, facilitate a more diverse range of political parties and candidates to run and it's associated with in a sense the growth of some of the minor parties in Australia."
The Senate
For Senate voting, a voter has two choices.
They can simply put the number 1 for their preferred party or candidate above the line or they can vote below the line for individual candidates.
If they vote below the line, they need to number at least twelve boxes.
Senate voting is counted in a different way to voting for the House of Representatives.
It uses a system of Proportional Representation, which is designed to secure the election of several candidates in each state - but still retains an element of preferential voting.
Successful candidates will have achieved more than a certain proportion of the total votes.
Candidates who have more than the required proportion of the votes have their surplus votes redistributed according to the voters' order of preference.
Once all the available positions are filled, the remaining candidates are eliminated.
Proportional representation has enabled small parties and independents to gain representation in the Senate.
