This class diagram represents a library management system. Members request a book, and the librarian creates a transaction and a bill. The member pays the bill and the librarian issues a book. Additionally, the book class connects to the author class, showing that each book has an author. The librarian has access to the library database.
Library management system diagram code in Gleek
About class diagrams
Class diagrams are used in software engineering to describe the structure of a system. A class diagram uses Unified Modeling Language (UML) to show the classes, attributes, methods (or operations), and their relationships to each other in the system. Class diagrams prove valuable in object-oriented modeling. Class diagrams can be used to model the data structure or to design a system in detail.