The Dewey Decimal System
The Dewey Decimal System organizes information into 10 broad areas, which are broken into smaller and smaller topics. Different topics are assigned numbers, known as "call numbers".
The general topics:
000s General Knowledge: Almanacs, Encyclopedias, Libraries, Museums, Newspapers...
100s Philosophy and Psychology: Death & Dying, Ethics, Feelings, Logic, Making Friends, Optical Illusions, Superstitions...
200s Religion and Mythology: Bible Stories, Buddhism, Christianity, Judaism, Islam, and other world religions; Greek, Roman, and other myths...
300s Social Sciences and Folklore: Careers, Customs, Environment, Families, Folktales, Government, Manners, Money, Recycling...
400s Languages and Grammar: World Languages, Sign Language, Dictionaries...
500s Math and Science: Animals, Biology, Chemistry, Dinosaurs, Fish, Geology, Insects, Physics, Planets, Plants..
600s Medicine and Technology: Cookbooks, Engineering, Farming, health, Human Body, Inventions, Nutrition...
700s Arts and Recreation: Architecture, Crafts, Drawing, Games, Jokes, Music, Sports...
800s Literature: Children's Literature, Plays, Poetry, Writing...
900s Geography and History: Biographies, Countries, Native Americans, States, Travel, Wars...