Mousse is a light, airy dessert or savory preparation made by folding whipped cream and/or whipped egg whites into a flavor base, giving it a soft, foam-like texture; the French word mousse means "foam."
Sweet mousses are commonly built on chocolate, fruit purée, or cheese, while savory versions can be built on seafood, such as crab or salmon, or on vegetables like roasted pepper or asparagus. The technique is generally credited to French cooks of the 18th century, who developed ways to fold whipped cream and egg whites into other ingredients without deflating them.
Mousse is served on its own in a glass or ramekin, or used as a filling for cakes, tarts, and pastries; savory mousses also appear as a topping for grilled fish or as a component of appetizers.