VN = visual novel. A game where usually the only way you interact with it is through choice prompts. The distinction gets fuzzy because you can absolutely do a RPG, a strategy game, a card-game or a deduction game that way, but it can't be anything with real-time control of your character like a shooter or platformer. I guess a pure VN is a game where all the interactions are choice prompts and none of the choices are solely gameplay-focused.