Terminology
When STV is used for single-winner elections, it is equivalent to the instant-runoff voting (alternative vote) method. To differentiate them, STV used for multi-winner elections is sometimes called proportional representation through the single transferable vote, or PR-STV. The term STV usually refers to the multi-winner version, as it does in this article. In Australia STV is known as the Hare–Clark Proportional method, while in the United States it is sometimes called choice voting, preferential voting or preference voting (note that preferential voting can alternatively refer to a broader category of voting systems: the ranked voting systems).
Read more about this topic: Single Transferable Vote