Fondant forms are getting more and more widespread so there is no need to explain what these are used for.
However for those who haven’t heard about that: Fondant forms are made mostly from silicone and we can create cake decoration with them from food ingredients, marzipan, sugar dough etc.
We can also cast food ingredients provided this substance is liquid enough, let say castable. But because in the kitchen we mostly use plastic substances for this purposes like marzipan, cake pastes, fondants etc. these are rather traced into the moulds then poured. The fondant itself can be very varied.
In general we call it fondant mass but we know honey fondant or fondant coat as well. It depends on what sort of material we use.
We can differentiate the fondants based on their shapes too. You can form a variety of little cute figures, recurring motifs, cake makers, pearl makers and so on.
We can also pour liquid (e.g simple or flavoured water) into the fondant molds and freeze or cook them later. This way we can prepare figures from ice to make the drink not only cold but also funny.