What Are Categories?
A category is a group of things that are alike in some way. Apples, bananas, and grapes are all in the category of FRUITS. Dogs, cats, and fish are all in the category of ANIMALS.
Sorting things into categories helps our brains organize information. Instead of remembering 20 random things, you can remember 4 categories with 5 things in each. That is much easier!
Think about a grocery store. Is all the food just piled in one big heap? No! It is organized into categories: fruits and vegetables in one area, bread in another, milk and cheese in the dairy section. Categories make it easy to find what you need.
When you write a category list, you pick a group and list all the things that belong in that group.