Dewey number

The Dewey Decimal System is a classification system used in libraries to organize books by subject. It assigns a unique three-digit number to each topic, allowing users to easily locate books. For example, books about psychology might be assigned the number 150, while those about history can fall under 900. This system helps librarians manage collections and assists readers in finding information efficiently. Named after Melvil Dewey, who developed it in the late 19th century, this method ensures a systematic arrangement of knowledge, making it easier for everyone to access information across diverse subjects.