Okay kiddo, do you know what a cookie is? Well, think of a wafer as a super thin and crispy cookie. It's made out of flour, water, and other ingredients that are mixed together and then baked until they become crunchy.
Wafer is not just one big cookie though. It's actually made up of many little circular cookies that are stuck together in a stack. These stacks can be used in lots of different ways like in ice cream sandwiches, as a base for cakes, or as a snack all on their own.
So the next time you eat an ice cream sandwich, remember that the crunchy layer that holds the ice cream together is made of wafers!