In first past the post elections like the one that just occurred, voters may be forced to vote strategically as opposed to preferentially.
For example, let's say a voter prefers a less popular candidate named RED, but he strongly dislikes a more popular candidate named YELLOW, and has mixed feelings about another more popular candidate named BLUE. The voter strategically votes for his #2 favourite option BLUE, instead of his #1 favourite option RED. He does this because he thinks that voting for RED would divide the vote for BLUE, who is the only candidate popular enough to stop YELLOW from winning.
This is called the spoiler effect, and it explains why a two party system forms in most democracies.
The result of first past the post elections can also be unfair. For example, although anonymously.deleted received the most votes, more than 50% of everyone did not vote for her. This means that a majority of voters are not satisfied with the result. Ranked choice instant runoff voting ensures that as many voters as possible are satisfied.
The way it works is that you vote by ranking the candidates in order of preference. The #1 choice votes are all counted. If nobody receives more than 50% of #1 choice votes, the least popular candidate is eliminated, and his/her #2 votes are distributed accordingly. This process is repeated until someone receives at least 50% of the vote.
This way, the result will ensure that the winner of the election will be someone at least half of the voters are satisfied with.