The scheme called Dewey Decimal Classification (DDC) was devised in 1876 by Melvil Dewey. This scheme is widely used in a majority of libraries in about 150 countries. Due to continuous revisions, the 23rd edition of DDC was published in July 2011. No other classification scheme has published so many editions. With suitable examples, this book explains the salient provisions of DDC 23. It will be useful to library professionals, as well as library and information science students.