The primary benefit of the Dewey Decimal System is that it catalogs books so that they can be easily located. Rather than having to randomly sort through stacks of books, or rely upon a system of alphabetization, students and researchers can find a book on a particular subject in a card catalog (paper or digital), then locate it on the book shelf. There the seeker will find other books on the same topic.
When Melvil Dewey invented his classification, he had no way of predicting how knowledge would evolve, and what new subjects books would cover. His system catalogs books into 10 broad categories; for example, general works is 000, pure sciences is 500 and fine arts is 700. These 10 broad subjects are further divided into sub categories, represented by the number to the right of the decimal. Beyond that, the number can get even more specific, and the classification even more precise, by expanding the number to include further numbers to the right of the decimal.
The Dewey Decimal System is used in more than 130 countries. The system translates since it uses all numbers, which has greater universality than letters and there is greater disparity in alphabets universally than numbers. More than 95 percent of public and school libraries use the system. In contrast, the Library of Congress System is used primarily in government and public libraries. The universality of the system means that once the basics are mastered, a student or researcher can locate books using the Dewey Decimal System no matter in which library they conduct research.
The Dewey Decimal System isn't the only book classification system used in libraries. The Library of Congress system is the dominant catalog in academic libraries. This system incorporates not only a number that signifies a particular subject matter, but also the author's last name and the year of the book's publication.