The Dewey Decimal Classification system was created in 1876 by a librarian named Melvil Dewey.

Dewey divided all the knowledge of the world into 10 main disciplines. Then he gave each main discipline of knowledge a number between 000 to 900. (SEE Table at left)

Dewey then subdivided each main discipline into smaller related topics and gave each of these topics a number. The smaller more specific topics were given decimal numbers.

Click on any of the the ten main disciplines to see how the Dewey Decimal Classification system works.