Fondant is used normally to cover cakes.  Or even just to make cake toppings. Fondant is like a thin coat of edible clay.

This video is showing you how to make a cake topper.  This video wants to teach you how to set up fondant and put it together.  Fondant can be refrigerated. Also keep all colored fondant out of direct light. Fondant cant really be used for many designs. Fondant is easier to use with a big cake than a small cake. The color of the fondant will fade in humidity.  Make sure you do not mix water and fondant. Again the colors will fade. Its easier to buy pre-colored fondant it’s less likely to fade.