Well you cast your vote in both. In the one you are choosing who you want to represent you and run the affairs of the parish/town/county/nation. Next time round you can change your mind or vote again for the same lot. Or you can vote tactically. There are various ways of deciding who’s won. In this country we have an unfair first-past-the-post system. In the other we are either voting for an irrevocable (more or less) decision to make a significant change (no next time round) or a reversible decision (another referendum is perfectly possible) to keep the status quo. Which is why an unqualified first-past-the-post setup is simply not right for referendums.