Definition: Dewey Decimal system

A book classification system for libraries that was created by Melvil Dewey in the 1870s and copyrighted in 1876. Used to this day in thousands of libraries worldwide, mostly for non-fiction content, the Dewey Decimal identification of a book is: subject (3 digits), decimal point, sub-section (1-3 digits) and first three letters of the name of the author or editor. For example, 612.6 WAT is a book classification.