Aperitifs are, essentially, "before dinner drinks". They may be served to mingling guests before a dinner party, during a course of appetizers or while preparing your own dinner on an average night after work. Think of the aperitif as a liquid appetizer.
Vermouth is the best known of the aromatised wines and a key part of many classic cocktails. The category not only includes red, white and rosé vermouth but Italian amaros; fernet, a bitter style of amaro.