![Use case diagrams are UML diagrams describing units of useful functionality (use cases) performed by a system in collaboration with external users (actors). Use case diagrams are UML diagrams describing units of useful functionality (use cases) performed by a system in collaboration with external users (actors).](https://www.uml-diagrams.org/use-case-diagrams/business-use-case-diagram-elements.png)
Use case diagrams are UML diagrams describing units of useful functionality (use cases) performed by a system in collaboration with external users (actors).
![Use Case Diagram, UML Diagrams Example: "Include" and "Extend" Use Cases - Visual Paradigm Community Circle Use Case Diagram, UML Diagrams Example: "Include" and "Extend" Use Cases - Visual Paradigm Community Circle](https://circle.visual-paradigm.com/wp-content/uploads/2017/08/Use-Case-Diagram-Include-and-Extend-Use-Cases-1-1280x720.png)
Use Case Diagram, UML Diagrams Example: "Include" and "Extend" Use Cases - Visual Paradigm Community Circle
![PDF) Generalization, Include (Uses), and Extend Relationships Verify Identity CREATING USE CASE DIAGRAMS | aini mukaromah - Academia.edu PDF) Generalization, Include (Uses), and Extend Relationships Verify Identity CREATING USE CASE DIAGRAMS | aini mukaromah - Academia.edu](https://0.academia-photos.com/attachment_thumbnails/37674575/mini_magick20190228-26132-osq76s.png?1551415714)