Can someone please explain the question and provide an example? I am very confused

"Here’s an exercise to get your brain to think in terms of classification—that is, inventing categories into which to divide a subject and then placing items into each category. As quickly as possible, divide each of the following subjects into as many categories as seems sensible. Keep a list of the categories. If, after rereading your list, a category doesn’t fit, delete it.
1. Exercise
2. Shoes
3. Electronic devices
4. Transportation
5. Homework
6. Drinks
7. Dreams
8. Meals"