Hey, small half-correction on your previous post. The method you were using for this is called Instant Runoff Voting. In Britain they usually call it the "alternative vote". Terms like "preferential voting" and "ranked choice voting" are also used, though personally I'm not a fan of these because they can theoretically describe a wide range of systems, even if in practice they usually mean IRV.
Single Transferable Vote is the system used when electing multiple winners. For example, in Australia we use STV to elect our Senate. Each state elects 6 Senators every 3 years, using STV. It's a somewhat-proportional system, and gets more proportional the larger number of winners there are. IRV, by contrast, is a single-winner system, suitable for outcomes where there can only be one winner (presidential races, for example, but also this kind of "choose a path to take" non-political vote).
Technically, it's true that STV where n=1 is basically identical to IRV, so it's not necessarily wrong per se. It is highly unconventional, however, to say STV for a single-winner situation.