The invention of the DDC has played a vital role in giving a direction and shape to the modern librarianship. It is not for nothing that Melvil Dewey is given the appellation of the father of modern librarianship.
The book has undergone 18 revisions to keep itself abreast of the ever advancing frontiers of knowledge and to cater to the increasing demand of its users. The 19th revision is presently underway. In every revision, it has been expanded, modified, rectified and made more modern in methods by applying the results of the latest research in library classification.
The book simply aims to introduce students to the process of assigning and especially synthesising the class numbers by the 19th edition of the DDC.