Library classification is a way to organize books into different categories so that it's easy to find the types of books you're looking for. It's like if you're looking for a cookbook, you can easily find all of the cookbooks in one spot. Libraries usually use a system called the Dewey Decimal System, which uses numbers to break books down into 10 main categories, like History or Science. Each of these main categories then have smaller categories underneath them. For example, History might include ancient history, modern history, and even a specific country or place. This way, it's easy to find the types of books you need.