You may be more familiar with the term "Rank-Choice Voting". Outside of the US, that system (ranking the candidates in order of your preference, with runoff or

You may be more familiar with the term "Rank-Choice Voting". Outside of the US, that system (ranking the candidates in order of your preference, with runoff or similar allocation methods in the case that nobody gets a majority) is called preferential voting. Being able to vote for any candidate on the ballot paper is a consequence of having a secret ballot system (nobody knows who you voted for), not preferential voting.