I thought souffles would be baked, while mousses would be only whipped, but I've seen recipes for cooked mousses before. Is this just a case of using the wrong name for the wrong recipe or are there important differences between them?
There is no strict delineation between these two terms. Either can be savory or sweet.
Some common differences are:
One might consider souffles a type of baked mousse, much as quiches are a specific type of tart, but that terminology is rarely used.
In my opinion