Super Class - is a group of classes. (optional) examples are Chevy, Mopar, Ford or Motorcycle.
Class - is what a car "item" will register in. Examples are Sport, Cruiser and Goldwing grouped by super class Motorcycle.
Categories - Is what is being judged on a scale from 1 to 10. Examples are Paint, Creativity, Craftsmanship, Overall Visual Impact.
Each class can have different categories.