Put them in order...
Preferential Voting is a method of balloting where you write down the candidates on your ballot in order, from most preferred to least preferred. Similar to how you might rank sports teams or restaurants from best to worst.
When tallying preferential ballots, you use the same rules for candidate elimination and determining a winner, as you do with multi-round tallying. Using preferential ballots saves time because voters only need to fill out and submit a ballot once, and tallying only happens once per office. Preferential Voting also make it more flexible for voters. If they happen to need to leave early, before some offices have come up for a vote, they can fill out their preferential ballots and put them in the ballot box before leaving.
Preferential Voting does have some disadvantages, primarily that you can’t change your mind between rounds. And it will have some effect on how voters vote, because they need to consider several candidates before voting.