From Wikipedia: frozen dessert: Frozen dessert is the generic name for desserts made by freezing liquids, semi-solids, and sometimes even solids. They may be based on flavored water (shave ice, sorbet, snow cones, etc.), on fruit purées, on milk and cream (most ice creams), on custard (frozen custard and some ice creams), on mousse (semifreddo), etc. In the UK and Ireland, where the term "dessert" is uncommon, frozen desserts are referred to as "ices".
In some countries including Canada, the term is often used on products which are similar in taste and texture to ice cream, but which do not meet the legal definition of that term (often being made primarily with vegetable oils, i.e. mellorine, as opposed to milk or cream).
No need to click the link -- that's all they have to say about frozen desserts. In some areas, you'll hear "ice cream and frozen desserts" to make the distinction because of the last paragraph of that Wiki article.
So many of these frozen treats exist nowadays. They are often defined by their packaging. Some are called ice-cream on a stick, frozen [flavor] on a stick, and I would have to ask the vendor for the names. I think that the vendors like to use the name frozen desserts for the batch because it gives the product an identity with a meal.