A use case diagram depicts interactions between elements of a system and can be used to model a library management system. A class diagram illustrates relationships between classes and their dependencies using UML. It defines methods and variables in objects. A data flow diagram is a graphical model of how data moves through an information system, showing processes and used as a preliminary overview of a system.

1. Submitted by
Kiran patel

2. What is use case diagram
A use case diagram is a graphic depiction of the interactions among
the elements of a system

3. Use case of library management

4. What is class diagram
A class diagram is an illustration of the relationships and source code
dependencies among classes in the Unified Modeling Language (UML).
 A class defines the methods and variables in an object, which is a specific
entity in a program or the unit of code representing that entity.

5. Class Diagram

6. What is DFD
A data flow diagram (DFD) is a graphical representation of the "flow"
of data through an information system, modeling its process aspects.
 A DFD is often used as a preliminary step to create an overview of
the system,