A. What a question! The Talmud (Pesachim) has a 9-way debate on it. All agree that we make a Havdalah (farewell to Shabbat) and Kiddush (welcoming YomTov) combination, but there are 9 varying opinions on the order of the blessings recited.
Our son Moshe did a Torah-Tuesday class on this very topic, titled YAKNAHAZ after learning about it in Talmud class at school.