How does it work?

The DDC system divides all knowledge into 10 main categories, each of which is divided into sub-categories. The system groups related items together according to discipline/subject, making it easier for the user to retrieve information. The 10 main broad categories are:

000 Generalities
100 Philosophy & psychology
200 Religion
300 Social sciences
400 Language
500 Natural sciences & mathematics
600 Technology (Applied sciences)
700 The arts - Fine and decorative arts
800 Literature & rhetoric
900 Geography & history

The DDC System moves from the general (broad) to the specific (narrow). Each of the above categories is divided into narrower sub - categories, for example:

300 Social sciences
310 Collections of general statistics
320 Political science
330 Economics
340 Law
350 Public administration & military science
360 Social problems & services; association
370 Education
380 Commerce, communication, transportation
390 Customs, etiquette, folklore

All the items in the Library have a call number (the Dewey number) printed on their spine, which indicates where the item is kept in the Library, i.e. with other items on the same subject.